Effect of different thresholds for CT perfusion volumetric analysis on estimated ischemic core and penumbral volumes.

PURPOSE: This single-center study compared three threshold settings for automated analysis of the ischemic core (IC) and penumbral volumes using computed tomographic perfusion, and their accuracy for predicting final infarct volume (FIV) in patients with anterior circulation acute ischemic stroke (AIS). METHODS: Fifty-two consecutive AIS patients undergoing mechanical thrombectomy (November 2015-March 2018) were included. Perfusion images were retrospectively analyzed using a single CT Neuro perfusion application (syngo.via 4.1, Siemens Healthcare GmbH). Three threshold values (S1-S3) were derived from another commercial package (RAPID; iSchema View) (S1), up-to-date syngo.via default values (S2), and adapted values for syngo.via from a reference study (S3). The results were compared with FIV determined by non-contrast CT. RESULTS: The median IC volume (mL) was 24.6 (interquartile range: 13.7-58.1) with S1 and 30.1 (20.1-53.1) with S2/S3. After removing the contralateral hemisphere from the analysis, the median IC volume decreased by 1.33(0-3.14) with S1 versus 9.13 (6.24-14.82) with S2/S3. The median penumbral volume (mL) was 74.52 (49.64-131.91), 77.86 (46.56-99.23), and 173.23 (125.86-200.64) for S1, S2, and S3, respectively. Limiting analysis to the affected hemisphere, the penumbral volume decreased by 1.6 (0.13-9.02), 19.29 (12.59-26.52), and 58.33 mL (45.53-74.84) for S1, S2, and S3, respectively. The correlation between IC and FIV was highest in patients with successful recanalization (n = 34, r = 0.784 for S1; r = 0.797 for S2/S3). CONCLUSION: Optimizing thresholds significantly improves the accuracy of estimated IC and penumbral volumes. Current recommended values produce diversified results. International guidelines based on larger multicenter studies should be established to support the standardization of volumetric analysis in clinical decision-making.

Association of Intracranial Aneurysms With Aortic Aneurysms in 125 Patients With Fusiform and 4253 Patients With Saccular Intracranial Aneurysms and Their Family Members and Population Controls.

Background Varying degrees of co-occurrence of intracranial aneurysms (IA) and aortic aneurysms (AA) have been reported. We sought to compare the risk for AA in fusiform intracranial aneurysms (fIA) and saccular intracranial aneurysms (sIA) disease and evaluate possible genetic connection between the fIA disease and AAs. Additionally, the characteristics and aneurysms of the fIA and sIA patients were compared. Methods and Results The Kuopio Intracranial Aneurysm Database includes all 4253 sIA and 125 fIA patients from its Eastern Finnish catchment population, and 13 009 matched population controls and 18 455 first-degree relatives to the IA patients were identified, and the Finnish national registers were used to identify the individuals with AA. A total of 33 fIA patients were studied using an exomic gene panel of 37 genes associated with AAs. Seventeen (14.4%) fIA patients and 48 (1.2%) sIA patients had a diagnosis of AA. Both fIA and sIA patients had AAs significantly more often than their controls (1.2% and 0.5%) or relatives (0.9% and 0.3%). In a competing risks Cox regression model, the presence of fIA was the strongest risk factor for AA (subdistribution hazard ratio 7.6, 95% CI 3.9-14.9, P<0.0005). One likely pathogenic variant in COL5A2 and 3 variants of unknown significance were identified in MYH11, COL11A1, and FBN1 in 4 fIA patients. Conclusions The prevalence of AAs is increased slightly in sIA patients and significantly in fIA patients. fIA patients are older and have more comorbid diseases than sIA patients but this alone does not explain their clinically significant AA risk.

Aneurysm Size is the Strongest Risk Factor for Intracranial Aneurysm Growth in the Eastern Finnish Population.

BACKGROUND: Saccular intracranial aneurysm (sIA) growth during follow-up is associated with high risk for subsequent rupture. Finnish patients have been suggested to have higher risk for subarachnoid hemorrhage, but follow-up studies of sIA growth in the Finnish population are scarce. OBJECTIVE: To identify the strongest risk factors for sIA growth in Eastern Finnish population by studying 205 patients with 350 unruptured sIAs with angiographic follow-up imaging. METHODS: In this population-based cohort study, we included unruptured sIA patients from the Kuopio University Hospital Intracranial Aneurysm Patient and Family database with at least 6 mo of angiographic follow-up after the diagnosis of sIAs. Angiograms were re-evaluated to detect aneurysms with growth of at least 1.0 mm. Cox regression analysis with patient- and aneurysm-related risk factors was used to calculate hazard ratios with 95% confidence intervals for growth. In addition, we tested the diagnostic value of previously introduced PHASES score for the prediction of sIA growth in Eastern Finnish population. RESULTS: Of the 350 unruptured aneurysms, 36 (10.3%) showed growth during median follow-up of 1.7 yr and total follow-up of 790 yr. In the multivariate Cox regression analysis, sIA size and location in the middle cerebral artery were significant risk factors for sIA growth. In receiver operator characteristic curves, both PHASES score and sIA size had relatively low areas under the curve. CONCLUSION: Our study indicates that aneurysm size is the strongest risk factor for aneurysm growth in Eastern Finnish population. Further studies are required to identify new risk factors for aneurysm growth.

Irregular Shape Identifies Ruptured Intracranial Aneurysm in Subarachnoid Hemorrhage Patients With Multiple Aneurysms.

BACKGROUND AND PURPOSE: We investigated which aneurysm-related risk factors for rupture best discriminate ruptured versus unruptured saccular intracranial aneurysms (sIAs) in subarachnoid hemorrhage patients with multiple sIAs. METHODS: We included 264 subarachnoid hemorrhage patients with a ruptured sIA and at least one additional unruptured sIA, from the Kuopio Intracranial Aneurysm database from 2003 to 2015. These patients had 268 ruptured and 445 unruptured sIAs. Angiograms of the 713 sIAs were reevaluated for multiple variables describing aneurysm shape. Multivariate generalized linear mixed models were used to calculate odds ratios with corresponding 95% confidence intervals for the independent risk factors for aneurysm rupture. RESULTS: In the multivariate analysis, only sIA size (P<0.004) and irregular shape (P<0.000) independently associated with sIA rupture. As an independent risk factor, irregular shape showed the strongest association with rupture (odds ratio 90.3; 95% confidence interval, 47.0-173.5). The sIA location, flow angles, bottleneck factor, or aspect ratio were not significantly associated with rupture. CONCLUSIONS: Irregular shape may identify the ruptured sIA better than size in patients presenting with aSAH and multiple sIAs.

Stent-assisted embolization of recurrent or residual intracranial aneurysms.

INTRODUCTION: Intracranial stents have theoretical advantages in the treatment of wide-necked intracranial aneurysms, but the usability of intracranial stents in the retreatment of recurrent intracranial aneurysms is relatively unknown. In this study, we aim to evaluate the safety and efficacy of stent-assisted embolization in the retreatment of recurrent or residual intracranial aneurysms. METHODS: Retrospective evaluation was carried out for 55 consecutive patients (17 men and 38 women; mean age 51.5 years), with 56 recurrent or residual intracranial aneurysms electively retreated with stent-assisted embolization. RESULTS: The technical success rate was 91% (50/55 patients). Procedural complications were encountered with six patients (11%). Angiographic and clinical follow-up data were available for 51 patients (93%), with a mean follow-up period of 28.1 months. No rebleedings were encountered during the study period. The clinical outcome was favorable in 50 patients (91%), with a Glasgow Outcome Score of 4 (N = 14) or 5 (N = 36) at the end of the study period. Poor clinical outcome correlated with very large (>2 cm) total aneurysm size (P = 0.002), large (>10 mm) recurrent aneurysm size (P = 0.011), and occurrence of periprocedural complications (P < 0.001). CONCLUSION: Stent-assisted coil embolization is beneficial for the retreatment of wide-necked recurrent or residual intracranial aneurysms, but stability and permanent occlusion of the recurrent aneurysm is unlikely if the aneurysm exceeds 2 cm in diameter, the recurrent diameter of the aneurysm exceeds 10 mm, or if mass effect is present with the recurrent aneurysm.

The silk flow-diverting stent in the endovascular treatment of complex intracranial aneurysms: technical aspects and midterm results in 24 consecutive patients.

BACKGROUND: The flow-diverting stent is a new option in endovascular therapy specifically designed for the endovascular reconstruction of a segmentally diseased artery. The safety of flow-diverting stents is still equivocal. OBJECTIVE: To evaluate the technical aspects, thromboembolic events, adjunctive therapies, and midterm results in patients with complex intracranial aneurysms treated with a flow-diverting stent (Silk; Balt Extrusion, Montmorency, France). METHODS: We retrospectively examined angiographic images and clinical reports of 24 consecutive patients (29 stents) treated (n = 23) or attempted to treat (n = 1) with a flow-diverting device in 2 Finnish centers between March 2009 and October 2010. RESULTS: The primary technical success rate was 67% (16/24). Adjunctive therapies were required in 6 (25%) patients, including 4 cases where intra-arterial abciximab was administered for the treatment of intraprocedural thromboembolic events. Technique-related complication rate and the 30-day mortality rate were each 4% (1/24). Follow-up imaging revealed 1 case of delayed in-stent thrombosis resulting in permanent disability of the patient, 1 asymptomatic occlusion, and 1 asymptomatic stenosis of the stented artery. Complete occlusion of the aneurysm with fully patent parent artery was observed in 16 of the 23 aneurysms (70%) where follow-up images were available. CONCLUSION: Many previously untreatable cerebral aneurysms may be successfully treated with the Silk flow-diverting stent, but the associated risk of thromboembolic events is justifiable only if conventional endovascular or surgical treatment options are not applicable. Perioperative thromboembolic events should be prepared for and treated without unnecessary delays because they frequently respond to adjunctive medical therapy.

Wide-necked intracranial aneurysms: treatment with stent-assisted coil embolization during acute (<72 hours) subarachnoid hemorrhage--experience in 61 consecutive patients.

PURPOSE: To evaluate the safety and efficacy of stent-assisted embolization of ruptured wide-necked intracranial aneurysms during acute subarachnoid hemorrhage (SAH). MATERIALS AND METHODS: Institutional review board approval for this retrospective study was obtained; the need to obtain informed consent was waived. Results in 61 consecutive patients (20 men, 41 women; mean age, 55.1 years; range, 26-83 years) with acutely ruptured wide-necked intracranial aneurysms who were treated with stent-assisted coil embolization were evaluated. The mean length of angiographic follow-up was 12.1 months (range, 0-52 months). Statistical analysis was performed to determine whether the features of the patient and the ruptured aneurysm affected the primary angiographic result or the patient's clinical outcome. Categoric and dichotomous variables were examined with the chi(2) test or the Fisher exact test; the Mann-Whitney U test and Kruskal-Wallis one-way analysis were used to compare continuous-scale data for non-normally distributed variables. RESULTS: The technical success rate was 72% (44 of 61). The technique-related complication rate was 21% (13 of 61), and the 30-day mortality rate was 20% (12 of 61). There was only one case of rebleeding, and clinical outcome was good for the majority of the patients (69% [42 of 61] had Glasgow Outcome Scale scores of 4 or 5 at the end of the study period). CONCLUSION: Stent-assisted coil embolization is a feasible method for the endovascular treatment of wide-necked intracranial aneurysms that are difficult to treat surgically or with balloon-assisted embolization during acute SAH. The risk of subsequent rerupture of the aneurysm seems to be reduced for aneurysms treated early compared with that for nonsecured aneurysms.