Comparing the safety and effectiveness of overlapping stents with flow diverters for unruptured vertebral artery dissecting aneurysms.

BACKGROUND: Endovascular treatment for vertebral artery dissecting aneurysms (VADAs) includes overlapping stents and flow diverters. This study compared the safety and effectiveness of overlapping stents and flow diverters for unruptured VADAs. METHODS: We retrospectively enrolled patients with unruptured VADAs who underwent overlapping stents or flow diverters at two tertiary hospitals in South Korea. The primary clinical outcome was the occurrence of stroke. The primary angiographic outcomes (>12 months) were categorized as regression, no decrease in size, recanalization, or stent occlusion, of which only regression was defined as a favorable angiographic outcomes. RESULTS: Of the 146 patients with VADAs, 25 (17.1%) had flow diverters and 121 (82.9%) had overlapping stents. For the primary angiographic outcomes over 12 months, the rate of favorable angiographic outcomes for flow diverters was 81.8% and for overlapping stents (triple stents) was 98.8% (P=0.006). In the multivariale analysis, after adjusting for partially thrombosed aneurysms, aneurysm shape, non-dominant vessel, posterior inferior cerebellar artery involvement, and procedure type, overlapping stents (triple stents) was not associated with favorable angiographic outcomes compared with flow diverters (OR 7.040, 95% CI 0.549 to 90.294; P=0.134), but partially thrombosed aneurysms was inversely associated with favorable angiographic outcomes (OR 0.056, 95% CI 0.005 to 0.589; P=0.016). The primary clinical outcome followed up to the last angiography did not occur in all patients. CONCLUSION: There was no difference in safety and effectiveness between overlapping stents and flow diverters in unruptured VADAs. Further endovascular treatment studies are needed regarding the association of partially thrombosed aneurysms with unfavorable angiographic outcomes.

The Impact of age and outcomes of high-risk patients on carotid revascularization.

OBJECTIVES: To validate the accuracy of high-risk criteria for carotid endarterectomy (CEA) and analyze the correlation between age and outcome of CEA and carotid artery stenting (CAS) in risk groups. METHODS: We reviewed a prospectively managed vascular surgery database in a single tertiary referral center, and 2482 internal carotid arteries (ICAs) had undergone carotid revascularization from November 1994 to December 2021. To validate high-risk criteria for CEA, patients were classified as high risk (Hr) and normal risk (Nr). Subgroup analysis was performed with patients older or younger than 75 years to investigate the relationship between age and outcome in each group. Primary endpoints were 30-day outcomes including stroke, death, stroke/death, myocardial infraction (MI), and major adverse cardiovascular events (MACEs). RESULTS: A total of 2345 ICAs in 2256 patients were enrolled. The number of patients in the Hr group was 543 (24%) and the number in the Nr group was 1713 (76%). CEA and CAS were performed on 1384 (61%) and 872 (39%) patients, respectively. The 30-day stroke/death rate was higher with CAS than CEA in both the Hr (1.1% vs. 3.9%, p = 0.032) and Nr (1.2% vs. 6.9%, p < 0.001) groups. In unmatched logistic regression analysis of the Nr group (n = 1778), the rate of 30-day stroke/death (OR, 5.575; 95% CI, 2.922-10.636; p < 0.001) was higher for CAS than CEA. In propensity score matching of the Nr group, the rate of 30-day stroke/death (OR, 5.165; 95% CI, 2.391-11.155; p < 0.001) was also higher for CAS than CEA. In the age <75 subgroup of the Hr group (n = 428), CAS was associated with higher 30-day stroke/death (OR, 14.089; 95% CI, 1.314-151.036; p = 0.029). In the age ≥75 subgroup of the Hr (n = 139), there was no difference in 30-day stroke/death between CEA and CAS. In the age <75 subgroup of the Nr group (n = 1318), 30-day stroke/death (OR, 6.300; 95% CI, 2.797-14.193; p < 0.001) was higher in CAS. In the age ≥75 subgroup of the Nr group (n = 460), 30-day stroke/death (OR, 6.468; 95% CI, 1.862-22.471; p = 0.003) was higher in CAS. CONCLUSIONS: In patients older than 75 years in the Hr group, there were relatively poor 30-day treatment outcomes in both CEA and CAS. Alternative treatment is needed that can expect better outcomes in older high-risk patients. In the Nr group, CEA has a significant benefit compared with CAS, and CEA should be recommended more to these patients.

Treatment results of carotid endarterectomy and carotid artery stenting for patients with radiation-induced carotid stenosis.

Purpose: Exposure to ionizing radiation over the head and neck accelerates atherosclerotic changes in the carotid arteries. Owing to the characteristics of radiation-induced carotid stenosis (RICS), the results regarding the optimal revascularization method for RICS vary. This study compared treatment outcomes between carotid endarterectomy (CEA) and carotid artery stenting (CAS) in RICS. Methods: This was a single-center retrospective review of consecutive patients who underwent CEA or CAS for carotid stenosis. RICS was defined as carotid stenosis (>50%) with the prior neck irradiation for cancer treatment on either side. For the analyses, demographics, comorbid conditions, carotid lesion characteristics based on imaging studies, surgical complications, neurologic outcomes, and mortality during the follow-up period were reviewed. To compare CEA and CAS results in RICS, a 1:1 propensity score matching was applied. Results: Between November 1994 and June 2021, 43 patients with RICS and 2,407 patients with non-RICS underwent carotid revascularization with CEA or CAS. RICS had fewer atherosclerotic risk factors and more frequent severe carotid stenosis and contralateral carotid occlusions than non-RICS. CAS was more commonly performed than CEA (22.9% vs. 77.1%) for RICS due to more frequent unfavorable carotid anatomy (0 vs. 16.2%). Procedure-related complications were more common in the CEA than in the CAS. However, there was no significant difference in neurologic outcomes and restenosis rates between CEA and CAS in RICS. Conclusion: Considering its lesion characteristics and cumulative incidence, RICS requires more attention than non-RICS. Although CAS has broader indications for RICS, CEA has shown acceptable results if selectively performed.

Significance of D-Dimer in Acute Ischemic Stroke Patients With Large Vessel Occlusion Accompanied by Active Cancer.

Background: This study aimed to investigate clinical outcome predictors of acute stroke patients with large vessel occlusion and active cancer and validate the significance of D-dimer levels for endovascular thrombectomy decisions. Methods: We analyzed a prospectively collected hospital-based stroke registry to determine clinical EVT outcomes of acute stroke patients within 24 h with following criteria: age ≥18 years, NIHSS ≥6, and internal carotid artery or middle cerebral artery lesion. All patients were classified into EVT and non-EVT groups. Patients were divided into two groups by initial D-dimer level. We explored variables potentially associated with successful recanalization as well as 3-month functional outcomes and mortality rates. Results: Among 68 patients, 36 were treated with EVT, with successful recanalization in 55.6%. The low D-dimer group showed a higher rate of successful recanalization and favorable outcome than the high D-dimer group. The mortality rate was higher in the high D-dimer group. No EVT and high D-dimer level were independent predictors of mortality, whereas lesion volume and low D-dimer level were independently associated with favorable outcomes. Conclusions: D-dimer level is a prognostic factor in acute LVO stroke patients with active cancer, and its high value for EVT decisions provisionally supports its testing in this patient population.

Perfusion recovery on TTP maps after endovascular stroke treatment might predict favorable neurological outcomes.

OBJECTIVES: Early recanalization and adequate collateral blood flow are surrogates for functional recovery in endovascular stroke treatment (EVT). We evaluated the prognostic value of pre- and immediate post-thrombectomy perfusion-weighted magnetic resonance imaging (PWI) parameters. METHODS: Consecutive patients with acute ischemic stroke who underwent EVT were enrolled. Lesion volumes and their corresponding changes on diffusion-weighted (DWI) and PWI were assessed. Outcome was measured with modified Rankin Scale (mRS) at 90 days, and early neurological improvement (> 8 points improvement on National Institutes of Health Stroke Scale [NIHSS] or 0 to 1) at 7 days. RESULTS: Fifty-two patients were enrolled. After control of initial NIHSS and recanalization status, post-thrombectomy time-to-peak (TTP) hypoperfused volume and TTP hypoperfused volume change remained independent predictors of favorable functional outcome (odds ratio [OR] = 0.13, 95% confidence interval [CI] = 0.03-0.54, p = 0.005; OR = 1.018, 95% CI = 1.00-1.03, p = 0.017), and early neurological improvement (OR = 0.20, 95% CI 0.07-0.58, p = 0.003; OR = 1.02, 95% CI = 1.00-1.03, p = 0.010). The areas under the curve of post-thrombectomy TTP hypoperfused volume and TTP hypoperfused volume change were 0.90 and 0.82 (cutoff 68 mL and 56 mL) for favorable outcome and 0.86 and 0.82 (cutoff 76 mL and 58 mL) for early neurological improvement, which had better prognostic values than other MR parameters and recanalization grades. CONCLUSIONS: These results suggest a large amount of perfusion recovery on TTP is associated with favorable outcome as well as early neurological improvement after EVT, and may be a useful prognostic marker. KEY POINTS: • A large amount of perfusion recovery on TTP map is associated with favorable outcome and early neurological improvement after EVT. • The best cutoff value for favorable functional outcome was 68 mL for post-EVT TTP hypoperfused volume and 56 mL decrease for TTP hypoperfused volume. • Amount of perfusion recovery on TTP map has better performance on the prediction of favorable functional recovery and early neurological improvement than other diffusion- and perfusion-weighted MRI parameters and recanalization grades.

Differentiation of postoperative changes and residual tumors in dynamic contrast-enhanced sella MRI after transsphenoidal resection of pituitary adenoma.

To establish magnetic resonance imaging (MRI) features that differentiate residual tumors from postoperative surgical changes following the transsphenoidal approach of a pituitary adenoma.We analyzed residual enhancements at the tumor bed in 52 patients who underwent dynamic contrast-enhanced sella MRI within 48 hours after surgery and at 6 to 28 months. Patients were divided into 2 groups defined by either peripheral or nodular enhancement patterns. For each group, we measured the maximum thickness of the residual enhancing portion and compared differences in the residual tumor and postoperative changes.Among the tumors examined in the 52 patients, 19 residual tumors showed nodular (n = 16) and peripheral (n = 3) enhancement patterns, and 33 postoperative changes showed nodular (n = 3) and peripheral (n = 30) enhancement patterns. The mean residual tumor thickness was 7.1 mm (range, 2.9-16.8 mm) and 1.9 mm (range, 1.0-7.4 mm) in the postoperative change. Receiver operating characteristic curve analysis revealed that a 3.9-mm thickness was associated with 89% sensitivity, 97% specificity, and 94% accuracy for diagnosis of residual tumor.On immediate postoperative MRI, residual enhancement with greater than 3.9-mm thickness and nodular pattern suggest residual pituitary adenoma tumor.

Need for rescue treatment and its implication: stent retriever versus contact aspiration thrombectomy.

BACKGROUD: The need for rescue treatment (RT) may differ depending on first-line modality (stent retriever (SR) or contact aspiration (CA)) in endovascular thrombectomy (EVT). We aimed to investigate whether the type of first-line modality in EVT was associated with the need for RT. METHODS: We identified all patients who underwent EVT for anterior circulation large-vessel occlusion from prospectively maintained registries of 17 stroke centers. Patients were dichotomized into SR-first and CA-first. RT involved switching to the other device, balloon angioplasty, permanent stenting, thrombolytics, glycoprotein IIb/IIIa antagonist, or any combination of these. We compared clinical characteristics, procedural details, and final recanalization rate between the two groups and assessed whether first-line modality type was associated with RT requirement and if this affected clinical outcome. RESULTS: A total of 955 patients underwent EVT using either SR-first (n=526) or CA-first (n=429). No difference occurred in the final recanalization rate between SR-first (82.1%) and CA-first (80.2%). However, recanalization with the first-line modality alone and first-pass recanalization rates were significantly higher in SR-first than in CA-first. CA-first had more device passes and higher RT rate. The RT group had significantly longer puncture-to-recanalization time (93±48 min versus 53±28 min). After adjustment, CA-first remained associated with RT (OR, 1.367; 95% CI, 1.019 to 1.834). RT was negatively associated with good outcome (OR, 0.597; 95% CI, 0.410 to 0.870). CONCLUSION: CA was associated with requiring RT, while recanalization with first-line modality alone and first-pass recanalization rates were higher with SR. RT was negatively associated with good outcome.

Outcomes of Stenting versus Endarterectomy for Symptomatic Extracranial Carotid Stenosis: A Retrospective Multicenter Study in Korea.

BACKGROUND: The present multicenter retrospective study aimed to compare the outcome of carotid artery stenting (CAS) versus carotid endarterectomy (CEA) among Korean patients with symptomatic extracranial carotid stenosis. METHODS: Between January 2008 and December 2011, 677 patients underwent either CAS (346, 51.1%) or CEA (331, 48.9%). The primary end point included the occurrence of major adverse cardiovascular events (MACEs), defined as fatal or nonfatal stroke and myocardial infarction, and all-cause mortality during the periprocedural period and within 4 years after CAS or CEA. RESULTS: Although patients undergoing CAS and CEA did not differ significantly in MACE incidence within 4 years (15.3% vs. 11.5%, P = 0.14), CEA showed lower periprocedural MACE incidence than CAS with clinical significance (6.1% vs. 3.0%, P = 0.06). During the periprocedural period, the incidence of any stroke was significantly higher in patients undergoing CAS (5.5% vs. 2.4%, P = 0.04) but not the incidence of myocardial infarction (0.6% vs. 0.3%, P > 0.99). Kaplan-Meier survival analysis showed similar MACE-free (P = 0.16), stroke-free (P = 0.24), and overall survival (P = 0.25) rates in both groups. On subgroup analysis, patients older than 70 years undergoing CAS had a significantly higher incidence of MACE at 4 years (22.7% vs. 13.7%, P = 0.03). CONCLUSIONS: Although the risk of MACE did not differ significantly within 4 years in this Korean population undergoing CAS and CEA, there was a higher risk of stroke with CAS during the periprocedural period.

Cav-1 (Caveolin-1) and Arterial Remodeling in Adult Moyamoya Disease.

Background and Purpose- Moyamoya disease (MMD) is a unique cerebrovascular occlusive disease characterized by progressive stenosis and negative remodeling of the distal internal carotid artery (ICA). We hypothesized that cav-1 (caveolin-1)-a protein that controls the regulation of endothelial vesicular trafficking and signal transduction-is associated with negative remodeling in MMD. Methods- We prospectively recruited 77 consecutive patients with MMD diagnosed via conventional angiography. Seventeen patients with intracranial atherosclerotic stroke and no RNF213 mutation served as controls. The outer distal ICA diameters were examined using high-resolution magnetic resonance imaging. We evaluated whether the degree of negative remodeling in the patients with MMD was associated with RNF213 polymorphism, cav-1 levels, or various clinical and vascular risk factors. We also investigated whether the derived factor was associated with negative remodeling at the cellular level using the tube formation and apoptosis assays. Results- The serum cav-1 level was lower in the patients with MMD than in the controls (0.47±0.29 versus 0.86±0.68 ng/mL; P=0.034). The mean ICA diameter was 2.48±0.98 mm for the 126 affected distal ICAs in patients with MMD and 3.84±0.42 mm for the asymptomatic ICAs in the controls ( P<0.001). After adjusting for confounders, cav-1 levels (coefficient, 1.018; P<0.001) were independently associated with the distal ICA diameter in patients with MMD. In vitro analysis showed that cav-1 downregulation suppressed angiogenesis in the endothelial cells and induced apoptosis in the smooth muscle cells. Conclusions- Our findings suggest that cav-1 may play a major role in negative arterial remodeling in MMD.

Caveolin-1, Ring finger protein 213, and endothelial function in Moyamoya disease.

BACKGROUND: Moyamoya disease is a unique cerebrovascular occlusive disease of unknown etiology. Ring finger protein 213 (RNF213) was identified as a susceptibility gene for Moyamoya disease in East Asian countries. However, the pathogenesis of Moyamoya disease remains unclear. METHODS: We prospectively analyzed clinical data for 139 patients with Moyamoya disease (108 bilateral Moyamoya disease, 31 unilateral Moyamoya disease), 61 patients with intracranial atherosclerotic stroke, and 68 healthy subjects. We compared the genetic (RNF213 variant) and protein biomarkers for caveolae (caveolin-1), angiogenesis (vascular endothelial growth factor (VEGF) and receptor (VEGFR2), and antagonizing cytokine (endostatin)) and endothelial dysfunction (asymmetric dimethylarginine (ADMA), and nitric oxide and its metabolites (nitrite and nitrate)) between patients with Moyamoya disease and intracranial atherosclerotic stroke. We then performed path analysis to evaluate whether a certain protein biomarker mediates the association between genes and Moyamoya disease. RESULTS: Caveolin-1 level was decreased in patients with Moyamoya disease and markedly decreased in RNF213 variant carriers. Circulating factors such as VEGF and VEGFR2 did not differ among the groups. Markers for endothelial dysfunction were significantly higher in patients with intracranial atherosclerotic stroke but normal in those with Moyamoya disease. Path analysis showed that the presence of the RNF213 variant was associated with caveolin-1 levels that could lead to Moyamoya disease. The level of combined marker of Moyamoya disease (caveolin-1) and intracranial atherosclerotic stroke (ADMA, an endothelial dysfunction marker) predicted Moyamoya disease with good sensitivity and specificity. CONCLUSION: Our results suggest that Moyamoya disease is a caveolae disorder but is not related to endothelial dysfunction or dysregulation of circulating cytokines.

A Polymorphism in RNF213 Is a Susceptibility Gene for Intracranial Atherosclerosis.

BACKGROUND: Both intracranial atherosclerotic stenosis (ICAS) and moyamoya disease (MMD) are prevalent in Asians. We hypothesized that the Ring Finger protein 213 gene polymorphism (RNF213), a susceptibility locus for MMD in East Asians, is also a susceptibility gene for ICAS in patients whose diagnosis had been confirmed by conventional angiography (absence of basal collaterals) and high-resolution MRI (HR-MRI, presence of plaque). METHODS: We analyzed 532 consecutive patients with ischemic events in the middle cerebral artery (MCA) distribution and relevant stenotic lesion on the distal internal carotid artery or proximal MCA, but no demonstrable carotid or cardiac embolism sources. Additional angiography was performed on 370 (69.5%) patients and HR-MRI on 283 (53.2%) patients. RESULTS: Based on angiographic and HR-MRI findings, 234 patients were diagnosed with ICAS and 288 with MMD. The RNF213 variant was observed in 50 (21.4%) ICAS patients and in 119 (69.1%) MMD patients. The variant was observed in 25.2% of patients with HR-MRI-confirmed ICAS. Similarly, 15.8% of ICAS patients in whom MMD was excluded by angiography had this variant. Among the ICAS patients, RNF213 variant carriers were younger and more likely to have a family history of MMD than non-carriers were. Multivariate testing showed that only the age of ICAS onset was independently associated with the RNF213 variant (odds ratio, 0.97; 95% CI, 0.944-0.99). CONCLUSIONS: RNF213 is a susceptibility gene not only for MMD but also for ICAS in East Asians. Further studies are needed on RNF213 variants in ICAS patients outside East Asian populations.

Multiparametric MR imaging of tumor response to intraarterial chemotherapy in orthotopic xenograft models of human metastatic brain tumor.

The purpose of our study was to investigate the therapeutic efficacy of intraarterial (IA) chemotherapy via multiparametric magnetic resonance imaging (MRI) analysis in orthotopic mouse brain tumor models. Stereotactic-guided intracranial inoculation of MDA-MB-231 cells was performed in nude mice. Thirty tumor bearing mice were randomized into three groups, and each group received either IA docetaxel administration (n = 10), intravenous (IV) docetaxel administration (n = 10), or IA solvent injection (n = 10) as control. Treatment response was monitored by diffusion-weighted imaging and dynamic contrast enhanced-MRI obtained 1 day before and 8 days after therapy initiation. Imaging results were correlated with histopathology. In the results, IA chemotherapy showed a significant decrease in tumor volume (86.5 ± 15.6 %) compared to the IV chemotherapy (121.1 ± 39.6%) and control (126.2 ± 22.0%) 8 days after therapy (p < 0.05). Furthermore, IA chemotherapy resulted in a significant increase in mean tumor apparent diffusion coefficient (ADC) values (116.8 ± 44.9%); in contrary IV chemotherapy (66.6 ± 26.9%) and control (69.1 ± 29.5%) showed a significant decrease in ADC values corresponding to further tumor growth (p < 0.05). However, there was no significant difference in perfusion parameters including initial area under the curve, K(trans), K(ep), and V(e) between the groups (p > 0.05). Histopathology confirmed necrosis and necroptosis in the tumors after IA chemotherapy. In conclusion, IA chemotherapy may lead to effective inhibition of tumor cell proliferation and offer potential benefit of inducing higher degree of treatment response than IV chemotherapy.

Endovascular treatment of unruptured ophthalmic artery aneurysms: clinical usefulness of the balloon occlusion test in predicting vision outcomes after coil embolization.

BACKGROUND: Endovascular coil embolization for ophthalmic artery (OphA) aneurysms has the latent risk of occlusion of the OphA during the procedure, which can lead to loss of vision. We report clinical and angiographic results of endovascular treatment of OphA aneurysms together with the efficacy of the balloon occlusion test (BOT). METHODS: From August 2005 to December 2013, 31 consecutive patients with 33 OphA aneurysms were treated in our institution. The patients were classified into two groups according to the location of the OphA within the aneurysmal sac. The BOT was performed in 28 patients using a hypercompliant balloon before endovascular coiling. Collateral circulation between the external carotid artery and the OphA was examined and visual function tests were performed before and after treatment. Patient demographics, angiographic and clinical outcomes were reviewed. RESULTS: Among the 28 patients who underwent the BOT, intact collateral circulation was demonstrated in 26 (92.9%) patients and complete occlusion of the OphA was obtained in three patients after coiling. Retrograde filling of the OphA with choroidoretinal blush was observed on post-procedural angiography and no specific visual symptoms were reported during the follow-up period. Complete embolization was achieved in 30 lesions (96.8%) and only five patients (16.1%) had minor recanalization. CONCLUSIONS: Endovascular treatment of OphA aneurysms can be performed safely and effectively in conjunction with BOT. The BOT may give useful information to predict visual outcome in patients whose OphA is likely to be threatened by the coiling procedure and to determine the optimal treatment strategy.

Adult Moyamoya Disease: A Burden of Intracranial Stenosis in East Asians?

BACKGROUND: Both Moyamoya disease (MMD) and intracranial atherosclerotic stenosis (ICAS) are more prevalent in Asians than in Westerners. We hypothesized that a substantial proportion of patients with adult-onset MMD were misclassified as having ICAS, which may in part explain the high prevalence of intracranial atherosclerotic stroke in Asians. METHOD: We analyzed 352 consecutive patients with ischemic events within the MCA distribution and relevant intracranial arterial stenosis, but no demonstrable carotid or cardiac embolism sources. Conventional angiography was performed in 249 (70.7%) patients, and the remains underwent MRA. The occurrence of the c.14429G>A (p.Arg4810Lys) variant in ring finger protein 213 (RNF213) was analyzed. This gene was recently identified as a susceptibility gene for MMD in East Asians. RESULTS: The p.Arg4810Lys variant was observed in half of patients with intracranial stenosis (176 of 352, 50.0%), in no healthy control subjects (n = 51), and in 3.2% of stroke control subjects (4 of 124 patients with other etiologies). The presence of basal collaterals, bilateral involvement on angiography, and absence of diabetes were independently associated with the presence of the RNF213 variant. Among 131 patients who met all three diagnostic criteria and were diagnosed with MMD, three-fourths (75.6%) had this variant. However, a significant proportion of patients who met two criteria (57.7%), one criterion (28.6%), or no criteria (20.0%) also had this variant. Some of them developed typical angiographic findings of MMD on follow-up angiography. CONCLUSIONS: Careful consideration of MMD is needed when diagnosing ICAS because differential therapeutic strategies are required for these diseases and due to the limitations of the current diagnostic criteria for MMD.

Delayed thromboembolic events more than 30 days after self expandable intracranial stent-assisted embolization of unruptured intracranial aneurysms.

OBJECTIVE: The Enterprise stent is used for endovascular treatment of complex intracranial aneurysms. The purpose of this study was to evaluate delayed thromboembolic events (DTEs) that developed more than 30 days after Enterprise stent-assisted embolization (SAC) and its associated risk factors. METHODS: There were 125 consecutive patients (90 women and 35 men; mean age, 56.1 years) who received endovascular treatment for 126 complex intracranial aneurysms using the Enterprise stent during December 2008 to May 2011. A DTE was defined as a symptomatic or asymptomatic ischemic stroke with positive findings on brain magnetic resonance imaging in the territory of the treated aneurysm and transient ischemic attack. Asymptomatic in-stent stenosis and occlusion were excluded. RESULTS: During a mean follow-up of 32.4 months, DTEs occurred in 10 patients (7.93%). DTEs occurred on antiplatelet therapy (dual medication, n = 2, 2 months after embolization; single medication, n = 6, 10-20 months after SAC) or after discontinuation of antiplatelet therapy (n = 2, 14 months after embolization). Multivariate analysis showed that current smoking (p = 0.005) and maximum parent artery diameter >4.5mm (p = 0.003) were associated with DTE. CONCLUSIONS: SAC with the Enterprise stent poses a considerable risk of DTE. Our results suggest that a longer duration of antiplatelet therapy and clinical follow-up may be warranted for cases with suggested risk factors. The protocol for antiplatelet therapy after SAC should be determined in a large prospective trial.

Long-term results of ethanol sclerotherapy with or without adjunctive surgery for head and neck arteriovenous malformations.

INTRODUCTION: Ethanol sclerotherapy has shown favorable short-term efficacy in managing head and neck arteriovenous malformation (AVM) which is well known for high recurrence rate after treatment. The purpose of this study was to report immediate treatment results and long-term follow-up results of ethanol sclerotherapy in patients with head and neck AVMs. METHODS: We performed a retrospective review of 45 patients with head and neck AVMs treated between April 1997 and December 2013 by using ethanol sclerotherapy with or without adjunctive surgery. The degree of AVM eradication was analyzed, and complications per treatment session were recorded. Long-term treatment effectiveness was assessed with clinical and imaging follow-up. RESULTS: In total, 132 sclerotherapies were performed in the 45 patients, with a total angiographic eradication rate of 17.8% (n = 8). Partial resolution was achieved in 34 patients, and three patients showed no response. Mean follow-up period was 56.6 months (range, 13-144 months). The long-term recurrence rate was 11.1% (5/45), and all recurrences occurred more than 3 years after the treatment with interval disease-controlled period. The major complication rate was 3.8% (5/132), and 34 minor complications (25.8%) occurred. CONCLUSIONS: Ethanol sclerotherapy is effective for achieving long-term durable cure of head and neck AVMs. In patients with non-curable disease, it is also effective for symptom palliation and long-term disease control. However, given recurrence after interval disease-controlled period, long-term follow-up should be required to detect recurrence in patients with any residual lesion after treatment.

Jostent covered stent placement for emergency reconstruction of a ruptured internal carotid artery during or after transsphenoidal surgery.

OBJECT: Internal carotid artery (ICA) rupture during transsphenoidal surgery (TSS) is an extremely difficult complication to treat. This study aimed to evaluate the immediate and long-term outcomes of covered stent placement for emergency reconstruction of ruptured ICAs during or after TSS. METHODS: Seven patients underwent covered stent placement for emergency reconstruction of a ruptured ICA during or after TSS. The safety and effectiveness of covered stent placement for emergency reconstruction of ruptured ICAs were retrospectively analyzed. RESULTS: Pretreatment angiography showed active bleeding in 6 patients (5 intraoperative and 1 postoperative) and a pseudoaneurysm in 1 patient. Of the 6 patients with active bleeding, 5 were treated with a successive operation to control active bleeding. The other patient was treated just after cardiopulmonary resuscitation due to massive nasal bleeding 20 days after revision of TSS. All active bleeding was controlled immediately after covered stent insertion in these 6 patients. One patient showed a gap between the covered stent and ICA wall without active bleeding 30 minutes after glycoprotein IIb/IIIa inhibitor administration due to in-stent thrombosis. The gap was occluded with coil embolization after completion of the temporarily suspended TSS. The seventh patient, whose ICA tear was treated with surgical suture, underwent covered stent placement for a pseudoaneurysm detected on postoperative Day 2. During a mean follow-up period of 46 months (range 12-85 months), all patients had excellent outcomes (modified Rankin Scale score of 0). All the stented ICAs were patent on vascular imaging follow-up at a mean of 34 months (range 12-85 months). CONCLUSIONS: Covered stents appear to be a safe and effective option for emergency reconstruction of ruptured ICAs during or after TSS.

Impact of contralateral carotid or vertebral artery occlusion in patients undergoing carotid endarterectomy or carotid artery stenting.

OBJECTIVE: To determine the impact of contralateral carotid occlusion (CCO) and/or vertebral artery occlusion (VAO) on the development of early postoperative neurologic complications after carotid endarterectomy (CEA) or carotid artery stenting (CAS). METHODS: A retrospective analysis was conducted using a database of patients who underwent CEA (n = 698) or CAS (n = 455) at a single institution. Excluded were 44 CEAs synchronously performed with coronary artery bypass grafting and 76 CASs performed without an embolic protective device (n = 69) or that resulted in technical failures (n = 7). All CEAs were the conventional type and performed under general anesthesia, and carotid shunts were routinely used. Patients were categorized into three groups according to patency of the contralateral carotid and vertebral arteries: Group I (no CCO or VAO); Group II (CCO with or without VAO); Group III (with VAO but no CCO). CCO or VAO were diagnosed with two or more carotid imaging studies including duplex ultrasonography, computed tomography angiography, magnetic resonance angiography, or conventional carotid angiography. Patient groups were compared with demographics, preoperative symptomatic status, and frequencies of early (<30 days) symptomatic neurologic complications (ESNCs) including transient ischemic attack and stroke. Postprocedural stroke alone was separately compared. Univariate (χ(2) or Fisher's exact test) and multivariate analysis (multiple logistic regression) were conducted to determine predictors of ESNC or postprocedural stroke. RESULTS: ESNCs and postprocedural stroke developed significantly more often with CAS compared with CEA (ESNC, 2.6% vs 8.1%; P < .001; stroke, 1.3% vs 6.8%; P < .001). In group II, the frequency of ESNCs was higher (6.8% vs 1.8%; P = .044), but the frequency of postprocedural stroke was not significantly higher (2.3% vs 0.9%; P = .405) in the CEA group. By multivariate analysis, the presenting symptom of stroke (odds ratio, 3.612; 95% confidence interval, 1.288-10.130; P = .015) and group II (odds ratio, 7.242; 95% confidence interval, 1.727-30.374; P = .007) were independent risk factors of ESNC following CEA but not CAS. When we analyzed the risk factor for postprocedural stroke alone, the presenting symptom of stroke was the only risk factor, while presence of CCO or VAO was not. CONCLUSIONS: CAS was followed by a significantly higher frequency of ESNC and postprocedural stroke compared with CEA. By subgroup analysis, CCO was a risk factor for ESNC but not for postprocedural stroke alone in patients undergoing CEA. Unilateral or bilateral VAO was not associated with a higher rate of ESNC or stroke in CEA or CAS.

Analysis of the layering pattern of the apparent diffusion coefficient (ADC) for differentiation of radiation necrosis from tumour progression.

OBJECTIVES: To evaluate the added value of diffusion-weighted imaging (DWI) to perfusion-weighted imaging (PWI) for differentiating tumour progression from radiation necrosis. METHODS: Sixteen consecutive patients who underwent removal of a metastatic brain tumour that increased in size after stereotactic radiosurgery were retrospectively reviewed. The layering of the ADC was categorised into three patterns. ADC values were measured on each layer, and the maximum rCBV was measured. rCBV and the layering pattern of the ADC of radiation necrosis and tumour progression were compared. RESULTS: Nine cases of radiation necrosis and seven cases of tumour progression were pathologically confirmed. Radiation necrosis (88.9 % vs. 14.3 %) showed a three-layer pattern of ADC with a middle layer of minimum ADC more frequently. If rCBV larger than 2.6 was used to differentiate radiation necrosis and tumour progression, the sensitivity was 100 % but specificity was 56 %. If the lesions with the three-layer pattern of ADC with moderately increased rCBV (2.6-4.1) were excluded from tumour progression, the sensitivity and specificity increased to 100 %. CONCLUSIONS: The three-layer pattern of ADC shows high specificity in diagnosing radiation necrosis; therefore, combined analysis of the ADC pattern with rCBV may have added value in the correct differentiation of tumour progression from radiation necrosis.

Unruptured non-branching site aneurysms located on the anterior (dorsal) wall of the supraclinoid internal carotid artery: aneurysmal characteristics and outcomes following endovascular treatment.

BACKGROUND: This study was undertaken to evaluate the aneurysmal characteristics and clinico-radiological outcomes of unruptured non-branching site aneurysms located on the anterior (dorsal) wall of the supraclinoid internal carotid artery (ICA). METHODS: The data of 34 patients that underwent endovascular treatment for 36 unruptured ICA anterior wall aneurysms were reviewed. ICA anterior wall aneurysms were defined as aneurysms that projected superiorly from the anterior wall of the ICA ophthalmic (n = 35) or communicating (n = 1) segment on lateral angiograms, without any branch vessel relationship. In addition, aneurysmal characteristics and treatment outcomes were compared with those of 60 unruptured aneurysms originating from the posterior (ventral) wall of the ICA ophthalmic segment. RESULTS: Patients with an ICA anterior wall aneurysm frequently had a mirror aneurysm on the contralateral side (14.7 % versus 3.3 %) or another ICA aneurysm (35.3 % versus 15 %). Two of the 36 ICA anterior wall aneurysms exhibited ICA narrowing suggestive of dissection, and another five had dysplastic ICA dilatation around the neck. Stent-assisted embolization was more frequently performed for ICA anterior wall aneurysms (66.7 % versus 36.7 %) because of unfavorable dome/neck (mean, 1.21) and aspect (mean, 1.15) ratios, and because of microcatheter instability associated with superior aneurysmal projections against the abrupt curvature of the carotid siphon. Procedure-related thromboembolic complications occurred in three patients in the anterior aneurysm group, but no patient deteriorated clinically. Immediate radiological outcomes were more unfavorable for ICA anterior wall aneurysms (residual sac, 36.1 % versus 16.7 %). Nevertheless, rates of recanalization (2.9 % versus 5.2 %) and progressive occlusion (24.7 % versus 8.1 %) during follow-up slightly favored ICA anterior wall aneurysms. Two stent-treated ICA anterior wall aneurysms developed asymptomatic ICA steno-occlusion (8.3 %). CONCLUSIONS: Stent-assisted embolization is safe and effective for the treatment of unruptured ICA anterior wall aneurysms exhibiting unfavorable aneurysmal geometries and projections for coil embolization.