Clinical Outcomes of Clipping and Coil Embolization for Ruptured Intracranial Aneurysms Categorized by Region and Hospital Size: A Nationwide Cohort Study in Korea.

BACKGROUND: To analyze the outcomes of clipping and coiling for ruptured intracranial aneurysms (RIAs) based on data from the National Health Insurance Service in South Korea, with a focus on variations according to region and hospital size. METHODS: This study analyzed the one-year mortality rates for patients with RIAs who underwent clipping or coiling in 2018. Coiling was further categorized into non-stent assisted coiling (NSAC) and stent assisted coiling (SAC). Hospitals were classified as tertiary referral general hospitals (TRGHs), general hospitals (GHs), or semi-general hospitals (sGHs) based on size. South Korea's administrative districts were divided into 15 regions for analysis. RESULTS: In 2018, there were 2,194 (33.1%) clipping procedures (TRGH, 985; GH, 827; sGH, 382) and 4,431 (66.9%) coiling procedures (TRGH, 1,642; GH, 2076; sGH, 713) performed for RIAs treatment. Among hospitals performing more than 20 treatments, the one-year mortality rates following clipping or coiling were 11.2% and 16.0%, respectively, with no significant difference observed. However, there was a significant difference in one-year mortality between NSAC and SAC (14.3% vs. 19.5%, P = 0.034), with clipping also showing significantly lower mortality compared to SAC (P = 0.019). No significant differences in other treatment modalities were observed according to hospital size, but clipping at TRGHs had significantly lower mortality than at GHs (P = 0.042). While no significant correlation was found between the number of treatments and outcomes at GHs, at TRGHs, a higher volume of clipping procedures was significantly associated with lower total mortality (P = 0.023) and mortality after clipping (P = 0.022). CONCLUSION: Using Korea NHIS data, mortality rates for RIAs showed no significant variation by hospital size due to coiling's prevalence. However, differences in clipping outcomes by hospital size and volume in TRGH highlight the need for national efforts to improve clipping skills and standardization. Additionally, the higher mortality rate with SAC emphasizes the importance of precise indications for its application.

Higher oscillatory shear index is related to aneurysm recanalization after coil embolization in posterior communicating artery aneurysms.

BACKGROUND: The recurrence rate of posterior communicating artery (Pcom) aneurysms after endovascular treatment (EVT) is higher than that for aneurysms located in other sites. However, it is still unclear what mechanisms are responsible for the recanalization of cerebral aneurysms. In this investigation, we compared hemodynamic factors related with recanalization of Pcom aneurysms treated by endoluminal coiling using computational fluid dynamics (CFD) with high-resolution three-dimensional digital subtraction angiography images. METHODS: Twenty patients were enrolled. A double-sinogram acquisition was performed with and without contrast injection after coil embolization to get true blood vessel lumen by relatively complementing the first sinogram with the second. Adaptive Cartesian meshing was performed to produce vascular wall objects for CFD simulation. The boundary condition for inlet (ICA) was set for dynamic velocity according to the cardiac cycle (0.8 s). Hemodynamic parameters were recorded at two specific points (branching point of Pcom and residual sac). The peak pressure, peak WSS, and oscillatory shear index (OSI) were recorded and analyzed. RESULTS: The median age was 61.0 years, and 18 patients (90%) were female. During a median follow-up of 12 months, seven (35%) treated aneurysms showed recanalization. The median aneurysm volume was significantly higher, and aneurysm height and neck sizes were significantly longer in the recanalization group than those in the stable group. At the branching point of the Pcom, the peak pressure, peak WSS, or OSI did not significantly differ between the two groups. The only statistically significant hemodynamic parameter related with recanalization was the OSI at the aneurysm point. Multivariate logistic regression showed that with an increase of 0.01 OSI at the aneurysm point, the odds ratio for the aneurysm recanalization was 1.19. CONCLUSIONS: A higher OSI is related with recanalization after coil embolization for a Pcom aneurysm.

Clinical Outcomes of Clipping and Coiling in Elderly Patients with Unruptured Cerebral Aneurysms: a National Cohort Study in Korea.

BACKGROUND: We aimed to analyze outcomes of clipping and coiling in treating unruptured intracranial aneurysms (UIAs) in elderly patients and to identify the age at which perioperative risk increases based on national cohort data in South Korea. METHODS: The incidence of perioperative intracranial hemorrhage (ICRH), perioperative cerebral infarction (CI), mortality, and moderate to severe disability data of the patients who underwent coiling or clipping for UIAs were retrieved. Estimated breakpoint (EBP) was calculated to identify the age at which the risk of treatment increases. RESULTS: A total of 38,207 patients were treated for UIAs. Among these, 22,093 (57.8%) patients underwent coiling and 16,114 (42.2%) patients underwent clipping. The incidence of ICRH, requiring a secondary operation, within 3 months in patients ≥ 65 years that underwent coiling and clipping was 1.13% and 4.81%, respectively, and that of both groups assessed were significantly higher in patients ≥ 75 years (coiling, P = 0.013, relative risk (RR) 1.81; clipping, P = 0.015) than younger patients. The incidence of CI within 3 months in patients aged ≥ 65 was 13.90% and 9.19% in the coiling and clipping groups, respectively. The incidence of CI after coiling in patients aged ≥ 75 years (P < 0.001, RR 1.96) and after clipping in patients aged ≥ 70 years (P < 0.001, RR 1.76) was significantly higher than that in younger patients. The mortality rates within 1 year in patients with perioperative ICRH or CI were 2.41% and 3.39% for coiling and clipping groups, respectively, in patients ≥ 65. These rates increased significantly at age 70 in the coiling group and at age 75 for the clipping group (P = 0.012 and P < 0.001, respectively). CONCLUSION: The risk of treatment increases with age, and this risk increases dramatically in patients aged ≥ 70 years. Therefore, the treatment decisions in patients aged ≥ 70 years should be made with utmost care.

Middle Meningeal Artery Embolization for Chronic Subdural Hematoma.

Purpose To evaluate the effect of middle meningeal artery (MMA) embolization on chronic subdural hematoma (CSDH) and compare the treatment outcomes of MMA embolization and conventional treatment. Materials and Methods All consecutive patients 20 years or older with CSDH were assessed for eligibility. CSDHs with a focal location, a thickness of 10 mm or less, no mass effect, or underlying conditions were excluded. Seventy-two prospectively enrolled patients with CSDH underwent MMA embolization (embolization group; as the sole treatment in 27 [37.5%] asymptomatic patients and with additional hematoma removal for symptom relief in 45 [62.5%] symptomatic patients). For comparison, 469 patients who underwent conventional treatment were included as a historical control group (conventional treatment group; close, nonsurgical follow-up in 67 [14.3%] and hematoma removal in 402 [85.7%] patients). Primary outcome was treatment failure defined as a composite of incomplete hematoma resolution (remaining or reaccumulated hematoma with thickness > 10 mm) or surgical rescue (hematoma removal for relief of symptoms that developed with continuous growth of initial or reaccumulated hematoma). Secondary outcomes included surgical rescue as a component of the primary outcome and treatment-related complication for safety measure. Six-month outcomes were compared between the study groups with logistic regression analysis. Results Spontaneous hematoma resolution was achieved in all of 27 asymptomatic patients undergoing embolization without direct hematoma removal. Hematoma reaccumulation occurred in one (2.2%) of 45 symptomatic patients receiving embolization with additional hematoma removal. Treatment failure rate in the embolization group was lower than in the conventional treatment group (one of 72 patients [1.4%] vs 129 of 469 patients [27.5%], respectively; adjusted odds ratio [OR], 0.056; 95% confidence interval [CI]: 0.011, 0.286; P = .001). Surgical rescue was less frequent in the embolization group (one of 72 patients [1.4%] vs 88 of 469 patients [18.8%]; adjusted OR, 0.094; 95% CI: 0.018, 0.488; P = .005). Treatment-related complication rate was not different between the two groups (0 of 72 patients vs 20 of 469 patients [4.3%]; adjusted OR, 0.145; 95% CI: 0.009, 2.469; P = .182). Conclusion MMA embolization has a positive therapeutic effect on CSDH and is more effective than conventional treatment. © RSNA, 2017.

The Relationship between Blood Pressure Variability, Recanalization Degree, and Clinical Outcome in Large Vessel Occlusive Stroke after an Intra-Arterial Thrombectomy.

BACKGROUND: Blood pressure variability (BPV) is associated with target organ damage progression and increased cardiovascular events, including stroke. The aim of this study was to evaluate the associations between short-term BPV during acute periods and recanalization degree, early neurological deterioration (END) occurrence, and functional outcomes in acute ischemic stroke patients who had undergone intra-arterial thrombectomy (IAT). METHODS: We retrospectively analyzed 303 patients with large vessel occlusive stroke who underwent IAT. The following BPV parameters, measured over 24 and 48 h after IAT, were compared: the mean, SD, coefficient of variation (CV), variation independent of the mean (VIM) for both the systolic BP (SBP) and diastolic BP, and the proportion of nocturnal SBP risers. RESULTS: BPV parameters decreased with higher recanalization degree. The mean SBP (SBPmean) over 24 and 48 h after IAT, and the SD of SBP (SBPSD), CV of SBP (SBPCV), and VIM of SBP (SBPVIM) during the 48 h following the procedure had significant associations with recanalization degree. Patients with END had higher BPV than that of those without END, and the difference was more evident for incomplete recanalization. Increased BPV was associated with a shift toward poor functional outcome at 3 months after adjustment, including recanalization degree (OR range for significant parameters, 1.26-1.64, p = 0.006 for 48 h SBPmean, p = 0.003 for 48 h SBPCV, otherwise p < 0.002). CONCLUSIONS: Short-term BPV over 24 and 48 h after IAT in acute ischemic stroke patients was related to recanalization degree, and END occurrence, and may be an independent predictor of clinical outcome.

Risk factor analysis of recanalization and retreatment for patients with endovascular treatment of internal carotid artery bifurcation aneurysms.

PURPOSE: Only a few reports of internal carotid artery (ICA) bifurcation aneurysms using the endovascular technique have been published in the current literature. The purpose of this study was to assess how multiple risk factors including angioarchitectural features of ICA bifurcation characteristics may have influenced aneurysmal rupture, recanalization, and retreatment. METHODS: Fifty-one patients with 52 ICA bifurcation aneurysms treated with endovascular coiling between July 2003 and July 2015 were retrospectively analyzed. The patients' clinical records, endovascular reports, and clinical and angiographic outcomes were reviewed. We also evaluated risk factors for recanalization and retreatment, including the angioarchitectural anatomy. RESULTS: The clinical outcomes were observed to be satisfactory in 49 patients (96.0%) and unfavorable in 2 patients (4.0%). The risk factor for aneurysmal rupture was young age (P = 0.024). Symptomatic complications due to thromboembolism occurred in 1.9% of cases; no patients suffered a fatal complication. Eleven of 52 ICA bifurcation aneurysms (21.2%) were recanalized within an average of 54.3 ± 33.5 months of follow-up. Among the aneurysms, 4 (7.7%) underwent recoiling. Multivariate analysis showed that ruptured aneurysms (P = 0.006) and a lower packing density (P = 0.048) were risk factors for recanalization. A lower packing density was the only risk factor for retreatment (P = 0.019). CONCLUSION: Endovascular treatment of ICA bifurcation aneurysms is considered safe and acceptable. This study showed that the ICA bifurcation aneurysms ruptured more frequently at a younger age. A higher packing density has been shown to reduce major recanalization and retreatment.

Endovascular coiling of proximal middle cerebral artery aneurysms: is it safe and durable?

BACKGROUND: Proximal middle cerebral artery (M1 segment) aneurysms are relatively deeply located in neighboring lenticulostriate arteries, which make them unsuitable for microsurgery. We aimed to investigate the clinical and radiological outcomes of endovascular coiling of M1 segment aneurysms. METHODS: Between January 2003 and December 2014, we retrospectively reviewed the medical records of 52 patients (52 aneurysms) from four institutions who underwent endovascular coiling of M1 segment aneurysms. Patients who underwent clinical and radiologic follow-up for more than a year after the procedure were evaluated. RESULTS: The aneurysms were located in the early frontal branch, early temporal branch, and lenticulostriate artery in 28, 15, and nine patients, respectively. Endovascular coiling was achieved in 51 cases and failed in one case. Of these 51 cases, 46 (90.2%) and five (9.8%) were non-ruptured and ruptured aneurysms, respectively. Initial angiographic results revealed complete occlusion in 26 (51.0%), residual neck in 16 (31.4%), and residual sac in nine (17.6%) cases. One failed case had a symptomatic procedural complication of thromboembolism. However, there was no permanent morbidity or mortality. Two major recanalization cases (3.9%) were retreated by endovascular coiling. On multivariable logistic regression analysis, aneurysmal recurrence was significantly related to aneurysm height (OR, 1.887; 95% CI, 1.107 to 3.217; p = 0.020), width (OR, 1.836; CI, 1.127 to 2.992; p = 0.015), and neck (OR, 4.017; CI, 1.220 to 13.232, p = 0.022). CONCLUSION: Endovascular coiling of M1 segment aneurysms appeared to be a feasible treatment option with a relatively low-retreatment rate. Aneurysm size was statistically significantly associated with recurrence.

Dose-Dependent Effect of Statin Pretreatment on Preventing the Periprocedural Complications of Carotid Artery Stenting.

BACKGROUND AND PURPOSE: We investigated whether statin pretreatment can dose dependently reduce periprocedural complications in patients undergoing carotid artery stenting because of symptomatic carotid artery stenosis. METHODS: We enrolled a consecutive series of 397 symptomatic carotid artery stenosis (≥50% stenosis on conventional angiography) treated with carotid artery stenting at 2 tertiary university hospitals over a decade. Definition of periprocedural complications included any stroke, myocardial infarction, and death within 1 month after or during the procedure. Statin pretreatment was divided into 3 categories according to the atorvastatin equivalent dose: none (n=158; 39.8%), standard dose (<40 mg of atorvastatin, n=155; 39.0%), and high dose (≥40 mg; n=84; 21.2%). A multivariable logistic regression analysis with the generalized estimating equation method was used to investigate independent factors in periprocedural complications. RESULTS: The patients' mean age was 68.7 years (81.6% men). The periprocedural complication rates across the 3 categories of statin use were 12.0%, 4.5%, and 1.2%. After adjustment, a change in the atorvastatin dose category was associated with reduction in the odds of periprocedural complications for each change in dose category (standard-dose statin: odds ratio, 0.24; 95% confidence interval, 0.07-0.81; high-dose statin: odds ratio, 0.11; 95% confidence interval, 0.01-0.96; P for trend=0.01). Administration of antiplatelet drugs was also an independent factor in periprocedural complications (OR, 0.18; 95% CI, 0.05-0.69). CONCLUSIONS: This study shows that statin pretreatment may reduce the incidence of periprocedural complications dose dependently in patients with symptomatic carotid artery stenting.

P2Y12 Reaction Units Threshold for Implementing Modified Antiplatelet Preparation in Coil Embolization of Unruptured Aneurysms: A Prospective Validation Study.

Purpose To identify and apply an optimized P2Y12 reaction units (PRU) threshold for implementing modified antiplatelet preparation to prevent thromboembolic events in patients nonresponsive to clopidogrel (clopidogrel nonresponders) undergoing coil embolization of unruptured aneurysms and to evaluate the clinical validity. Materials and Methods The optimal PRU threshold for prediction of thromboembolic events was determined with the Youden index in post hoc analysis of a previous, prospectively enrolled cohort of 165 patients in whom the antiplatelet regimen was not modified. This optimal PRU threshold was used to define clopidogrel nonresponders in a prospective validation study of 244 patients. Standard preparation (aspirin, clopidogrel) was maintained for 126 patients responsive to clopidogrel (clopidogrel responders, 51.6%), and modified preparation (aspirin, prasugrel) was prescribed prior to embolization for 118 clopidogrel nonresponders (48.4%). Fifty-seven clopidogrel nonresponders from the previous cohort who did not receive the modified preparation were included as a historical control group. Thromboembolic and bleeding events were compared among groups by using logistic regression analysis. Results Post hoc analysis from the previous cohort yielded PRU of at least 220 as the optimal threshold for modified preparation selection. The thromboembolic event rate of the clopidogrel responders (one of 126 [0.8%]) was lower than that of the historical control group that received standard preparation (seven of 57 patients [12.3%]; adjusted risk difference [RD], -10.1%; 95% confidence interval [CI]: -18.5, -1.7; P = .015) and was similar to that of clopidogrel nonresponders who received modified preparation (one of 118 [0.8%]; adjusted RD, -0.5%; 95% CI: -3.1, 2.1; P = .001 for noninferiority; P = .699 for superiority). Bleeding event rates did not differ among groups (four of 126 clopidogrel responders [3.2%] vs four of 57 clopidogrel nonresponders that received standard preparation [7.0%] [adjusted RD, -4.5%; 95% CI: -11.1, 3.4; P = .228] vs five of 118 clopidogrel nonresponders that received modified preparation [4.2%] [adjusted RD, -0.6%; 95% CI: -5.8, 4.2; P = .813]). Conclusion Patients undergoing coil embolization of unruptured aneurysms, regardless of clopidogrel responsiveness, had low thromboembolic risk when using PRU of at least 220 as the threshold for implementing modified antiplatelet preparation with prasugrel. © RSNA, 2016 Online supplemental material is available for this article.

Impact of the Penumbral Pattern on Clinical Outcome in Patients with Successful Endovascular Revascularization.

BACKGROUND: In patients with acute ischemic stroke, the impact of penumbral patterns on clinical outcomes after endovascular treatment (EVT) remains controversial. We aimed to establish whether penumbral patterns are associated with clinical outcome after successful recanalization with EVT while adjusting for onset to revascularization time. MATERIALS AND METHODS: Using a web-based, multicenter, prospective stroke registry database, we identified patients with acute ischemic stroke who underwent perfusion and diffusion magnetic resonance imaging (MRI) before EVT, had anterior circulation stroke, received EVT within 12 hours of symptom onset, and had successful revascularization confirmed during EVT. Based on pretreatment MRI, patients were stratified as having a favorable or nonfavorable penumbral pattern. Onset to revascularization time was dichotomized by median value. Primary outcome was functional independence (modified Rankin Scale score ≤2) at 90 days. FINDINGS: Among 121 eligible patients from three university hospitals, 104 (86.0%) had a favorable penumbral pattern, and the median time to revascularization was 271 minutes (interquartile range, 196-371). The functionally independent patient proportion was higher in those with a favorable penumbral pattern than in those without (53.8% versus 5.9%; P <.001), but was not different between early and late revascularization groups (49.2% versus 45.0%; P = .65). The favorable penumbral pattern was associated with functional independence after adjusting confounders (odds ratio, 23.25; 95% confidence interval: 1.58-341.99; P = .02). Time to revascularization did not modify the association (P for interaction, .53). CONCLUSION: A favorable penumbral pattern is associated with improved functional independence in patients with endovascular revascularization, and the association was not time-dependent.

Major recanalization occurs more often in young patients after unruptured aneurysm coil embolization.

BACKGROUND: The recanalization rate after coil embolization of unruptured aneurysms was compared between young and old age groups. METHODS: From May 2003 to December 2010, 636 patients with 715 saccular unruptured intracranial aneurysms (UIA) underwent endovascular coiling and were followed for at least 6 months. For comparative analysis, patients were categorized into two groups according to age 40: 42 patients with 46 aneurysms who were 40 years or younger (young age group) and 594 patients with 669 aneurysms who were older than 40 years (old age group). Angiographic and clinical outcomes including recanalization rates were compared. RESULTS: Angiographically, class 1 or 2 occlusion according to the Raymond-Roy Occlusion Classification system was achieved in 89.2 % of the patients (91.3 % in the young age group and 89.1 % in the old age group, p = 0.74). Procedure-related complication rate was 2.2 % and 3.4 % in the young and the old age group (p = 0.16), respectively. The mean follow-up duration was 30.51 ± 18.59 months. Major recanalization occurred in seven aneurysms (15.2 %) in the young age group and in 44 aneurysms (6.6 %) in the old age group (p = 0.03). Retreatment was performed in seven patients (15.2 %) in the young age group and in 35 patients (5.2 %) in the old age group (p = 0.01). CONCLUSIONS: The present study showed that the technical feasibility and safety of endovascular coiling for UIA did not differ between the two age groups. However, the major recanalization rate was higher in the young age group.

Recanalization Rate and Clinical Outcome in Acute Carotid-T Occlusion.

BACKGROUND: Acute carotid-T occlusion results in both low recanalization rates and poor outcomes. We investigated clinical outcomes and recanalization in a rare case of thrombolytic therapy. METHODS: A consecutive series of patients with acute carotid-T occlusion who were treated with either bridging intravenous (IV) plus intra-arterial (IA) thrombolysis or IA alone were analyzed. Complete recanalization was defined as a thrombolysis in cerebral infarction (TICI) grade of 3. A favorable outcome was defined as a modified Rankin Scale (mRS) score of ≤2. RESULTS: Of the 40 patients, 6 (15%) had favorable outcomes, and 34 (85%) had poor outcomes. Favorable outcomes were significantly associated with a lower National Institutes of Health Stroke Scale (NIHSS) score after revascularization treatment and higher rates of complete recanalization (p < 0.01, p < 0.024, respectively). Complete recanalization was achieved in all patients with favorable clinical outcomes and 5 (83%) patients had received combined IV/IA thrombolysis (p = 0.381). CONCLUSIONS: The results suggest that complete recanalization for acute carotid-T occlusion improves clinical outcomes. In that regard, bridging IV/IA thrombolysis may be more efficacious than IA alone.

Early carotid artery stenting for symptomatic carotid artery stenosis.

BACKGROUND: The aim of present study was to assess safety and efficacy of early carotid artery stent (CAS) in patients with symptomatic carotid artery stenosis compared with delayed CAS. METHODS: This retrospective study was approved by the institutional review board, and the requirement to obtain written informed consent was waived. Outcomes of 206 patients with symptomatic carotid stenosis who were treated by CAS were analyzed. According to CAS timing from last symptom, patients were divided into early (within 2 weeks, 74 [35.0 %]) and delayed (after 2 weeks, 112 [64.1 %]) group by CAS timing from the last symptom. Procedural complication and early (≤30 days of CAS) event (ipsilateral stroke or any death) for safety, and late (31 days to 1 year of CAS) event for efficacy of CAS preventing further stroke were evaluated. The two groups were compared using Cox proportional hazard analysis. RESULTS: No difference was found in procedural complication between the groups (early 2 [2.7 %] vs. delayed group 7 [5.3 %], hazard ratio [HR] 0.61, 95 % confidence interval [CI] 0.123-2.979, p = 0.537). In the early group, however, early event developed more frequently than in the late group (9 [12.2 %] vs. 1 [0.8 %], HR 16.05, 95 % CI 1.991-129.438, p = 0.009). The late event rate showed no difference between the two groups (4 [5.4 %] vs. 4 [3.0 %], HR 2.09, 95 % CI 0.484-8.989, p = 0.324). CONCLUSIONS: Early CAS is not safe during periprocedural period, compared with late CAS. In CAS for symptomatic carotid stenosis, delayed CAS should be considered.

Morphology and related hemodynamics of the internal carotid arteries of moyamoya patients.

BACKGROUND: Morphological studies investigating the intracranial-extradural internal carotid artery with moyamoya disease have not been reported. We designed this case-control study to investigate the morphological differences of the internal carotid artery with moyamoya disease, and to clarify the contributions of these differences to the resultant fluid dynamics. METHODS: Patients with moyamoya disease and normal controls were assigned to each group. The vascular tortuosity of internal carotid artery was measured with three-dimensional rendering using magnetic resonance angiography. By computational fluid dynamics, hemodynamic characteristics were simulated and compared between two groups. RESULTS: Distances were measured from the carotid canal to the siphon. A shorter actual distance was observed in the moyamoya group (p = 0.0170). Vascular tortuosity was significantly low in moyamoya patients showing lower curvature angles in the petrous and intra-cavernous segments (p = 0.0012). Less blood flowed (p < 0.0001) through the narrower internal carotid artery (p < 0.0001) in the moyamoya group at the carotid canal level. The blood flow velocities were not significantly different (p = 0.2332). Faster blood flow and higher wall shear stress in the internal carotid artery bifurcation were verified with computational fluid dynamics. CONCLUSIONS: Significant morphological differences were confirmed to exist in the intracranial-extradural internal carotid artery of moyamoya patients. These differences might influence the hemodynamics around the bifurcation of the internal carotid artery.

Delayed ischemic stroke after stent-assisted coil placement in cerebral aneurysm: characteristics and optimal duration of preventative dual antiplatelet therapy.

PURPOSE: To evaluate characteristics of delayed ischemic stroke after stent-assisted coil placement in cerebral aneurysms and to determine the optimal duration of dual antiplatelet therapy for its prevention. MATERIALS AND METHODS: This retrospective study was approved by the institutional review board, and the requirement to obtain written informed consent was waived. Of 1579 patients with 1661 aneurysms, 395 patients (25.0%) with 403 aneurysms (24.3%) treated with stent-assisted coil placement were included and assigned to groups stratified as early (126 patients [31.9%]; 3 months of coil placement), midterm (160 patients [40.5%]; 6 months), or late (109 patients [27.6%]; ≥ 9 months), according to the time points of switching dual antiplatelet therapy to monotherapy from coil placement. Cumulative rates of delayed ischemic stroke in each group were calculated by using Kaplan-Meier estimates that were compared with log-rank tests. Risk factors of delayed ischemic stroke were identified by using Cox proportional hazard analysis. RESULTS: Delayed ischemic stroke occurred in 3.5% of all cases (embolism, 3.0%; thrombotic occlusion, 0.5%) within 2 months following the switch. Late switch yielded no delayed ischemic stroke, unlike early (seven of 126 patients [5.6%]; P = .013) or midterm (seven of 160 patients [4.4%]; P = .028) switch. Incomplete occlusion (hazard ratio, 6.68 [95% confidence interval: 1.490, 29.900]) was identified as a risk factor. CONCLUSION: Delayed ischemic stroke after stent-assisted coil placement is caused by embolism from or thrombotic occlusion of stent-containing vessels after switching from dual antiplatelet therapy to monotherapy. The stent-containing vessel with incomplete aneurysm occlusion presents as a long-term thromboembolic source. Therefore, dual antiplatelet therapy for more than 9 months and late switch to monotherapy are recommended for its prevention.

A retrospective analysis on the natural history of incidental small paraclinoid unruptured aneurysm.

OBJECTIVE: The optimal consensus concerning treatment of incidental small paraclinoid unruptured intracranial aneurysms (UIAs) remains controversial. The aim of this retrospective study was to reveal the natural history of small paraclinoid UIAs with the goal of informing the treatment plan. METHODS: 524 patients harbouring 568 paraclinoid UIAs (≤5 mm) were retrospectively evaluated during the mean follow-up of 35.4 months. The aneurysms were divided into two groups with respect to arterial branch: related (ophthalmic and superior hypophyseal artery), and non-related. Medical records were reviewed concerning multiple variables, such as sex, age, hypertension (HTN), diabetes mellitus, smoking and aneurysmal factors (size, arterial relationship, multiplicity and the occurrence of rupture and growth). The cumulative risk and the risk factors of aneurysmal rupture and growth were analysed. RESULTS: Two aneurysmal (0.35%) ruptures and 17 growths (3.0%) were observed during the follow-up of 1675.5 aneurysm-years with an annual rupture of 0.12% and an annual growth of 1.01%. The cumulative survival without aneurysmal growth reached a significant difference in aneurysms ≥4 mm (p=0.001), HTN (p=0.002), and arterial branch-related location (p=0.001). Multivariate analysis disclosed that aneurysm ≥4 mm (HR, 4.41; p=0.003), HTN (HR, 5.74; p=0.003), arterial branch-related location (HR, 6.04; p=0.002), and multiplicity (HR, 0.27; p=0.042) were significant predictive factors for aneurysm growth. CONCLUSIONS: Although incidental small paraclinoid UIAs have a relatively lower rupture and growth risk, patients with high-risk factors, including aneurysm ≥4 mm, HTN, arterial branch-related aneurysms, and multiple aneurysms must be monitored closely. The limitation of the retrospective nature of this study should be taken into consideration.

Endovascular internal carotid artery trapping for ruptured blood blister-like aneurysms: long-term results from a single centre.

INTRODUCTION: Endovascular internal carotid artery (ICA) trapping was performed to treat ruptured blood blister-like aneurysms (BBAs). The aim of this study was to evaluate the procedural risks and long-term follow-up results. METHODS: The records of 11 consecutive patients with BBAs who underwent endovascular ICA trapping between 2005 and 2010 were reviewed. Clinical outcomes were assessed with modified Rankin Scale (mRS) scores. RESULTS: Endovascular ICA trapping was performed in 11 patients as either the primary treatment (7 patients) or the secondary treatment (4 patients) after the patient underwent other treatments. Three patients underwent superficial temporal artery (STA)-middle cerebral artery (MCA) bypass when balloon test occlusion (BTO) revealed inadequate collateral circulation. In the primary ICA trapping group (seven patients), six patients had good outcomes (mRS 0 in five, mRS 1 in one), and one patient had a poor outcome (mRS 6: dead). In the secondary ICA trapping group (four patients), two patients had good outcomes (mRS 0), and two patients had poor outcomes (mRS 4, 5). All ten of the surviving patients were clinically stable during the follow-up period (mean 39 months). A radiological follow-up of nine patients (mean 22 months) demonstrated stable occlusion, with the exception of one reopening of the ICA because of coil migration. Perfusion studies of nine patients (mean: 23 months) demonstrated no perfusion decrease. CONCLUSION: Endovascular ICA trapping is an effective and durable treatment for BBAs.

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.

Endovascular coil embolization of unruptured intracranial aneurysms: a Korean multicenter study.

BACKGROUND AND OBJECTIVE: Endovascular coil embolization has been a major treatment modality for unruptured intracranial aneurysms (UIAs) in South Korea. However, there are still few reports on the outcomes of this procedure. We performed a retrospective, multicenter study to determine how safe and effective coiling for UIA has been over the most recent 3 years in South Korea. MATERIALS AND METHODS: We analyzed a total of 2,180 UIAs in 2,035 patients who were treated by coiling from January 2007 to December 2009 at 22 centers in South Korea, with a focus on patient characteristics, the location and size of the aneurysms, procedural complications, and angiographic and clinical outcomes. RESULTS: Coiling was successful in 98.0 % of the cases (2,137/2,180 aneurysms). Immediate post-procedural angiography demonstrated complete occlusion in 62.6 % (1,337/2,137 aneurysms), residual neck in 32.4 % (692/2,137), and residual sac in 5.0 % (108/2,137) of the cases. The rate of any procedure-related adverse event was 6.9 % (148/2,137 aneurysms). The rates of permanent morbidity and mortality were 1.8 % (39/2,137 aneurysms) and 0.1 % (2/2,137 aneurysms), respectively. Follow-up conventional angiography or MRA at ≥6 months was performed in 85.7 % (1,832/2,137 aneurysms) of cases. Among the eligible aneurysms for follow-up angiographic analysis, major recanalization was noted in 3.9 % (72/1,832 aneurysms, mean follow-up interval, 12 months). Among these, 68 aneurysms (3.7 %) were re-treated. An aneurysm of the middle cerebral artery (MCA) was a risk factor for incomplete occlusion (P = 0.049) and major recanalization (P = 0.046). During follow-up, no aneurysmal rupture occurred. CONCLUSIONS: Endovascular coil embolization of UIAs has been an effective preventive modality with low procedure-related morbidity in South Korea.

Symptomatic steno-occlusion of cerebral arteries and subsequent ischemic events in patients with acute ischemic stroke.

BACKGROUND: We aimed to assess the impact of symptomatic steno-occlusion (SYSO) of cerebral arteries and its characteristics on subsequent ischemic event (SIE) in patients with acute ischemic stroke. METHODS: Using a prospective stroke registry database, we identified consecutive patients with ischemic stroke who were hospitalized within 48 hours of symptom onset. SYSO denoted significant stenosis or occlusion of major cerebral arteries with ischemic lesions at the corresponding arterial territories and was characterized by its location and severity. Primary outcome was SIE that was defined as ischemic progression or recurrence within 1 year. RESULTS: In total, 1546 patients (age, 67.4 ± 13.0 years; median National Institutes of Health Stroke Scale score, 4) were enrolled in this study. The cumulative risk of SIE was 14.5% at 7 days, 14.9% at 14 days, 15.5% at 90 days, and 16.9% at 1 year. Patients with SYSO had significantly higher SIE rates compared with those without SYSO (23.0% versus 11.6%). Of the characteristics of SYSO, the location, not the severity, was significantly associated with SIE (P < .001 and P = .186, respectively). Multiple (adjusted hazard ratio, 5.85; 95% confidence interval, 1.81-18.85), intracranial internal carotid artery (ICA) (3.54; 1.21-8.21), and extracranial ICA SYSO (2.88; 1.01-8.21) raised the risk of SIE. CONCLUSIONS: Subsequent cerebral ischemic events (progression or recurrence) after an acute ischemic stroke occur mostly within several days of stroke onset and is associated with the location, but not the severity, of symptomatic steno-occlusion of cerebral arteries.