H. Brunel

Flow-Diverter Silk Stent for the Treatment of Intracranial Aneurysms: 1-year Follow-Up in a Multicenter Study

BACKGROUND AND PURPOSE: FD stent placement is a promising therapy for challenging intracranial aneurysms. Long-term evaluations about angiographic and morphologic results are still missing. This is the aim of this multicenter series. MATERIALS AND METHODS: We report our experience and 1-year FU in a retrospective chart review of 65 consecutive subjects with 77 unruptured or recanalized aneurysms that were treated with Silk FD stents at 6 centers in France. Both angiographic and clinical results were recorded before treatment and at 6 and 12 months after treatment. At the 12-month FU, relationships between angiographic aneurysm occlusion and shrinkage of the thrombosed aneurysm sac were evaluated. RESULTS: Stent deployment was achieved in 64 cases (98.5%) and failed in 1 case (1.5%). Seven misdeployments of the Silk stent caused the occlusion of 6 parent arteries. Overall acute/subacute procedural morbidity was 7.7%, and mortality was zero. Delayed complications were observed in 10.9% of subjects. At the 6-month FU, permanent morbidity was 7.8% and mortality was 3%. Complete occlusion occurred within 6 months in 68% of aneurysms and within 12 months after treatment in 84.5% of aneurysms. At the 12-month FU, in angiographically complete occluded aneurysms, MR imaging/CT analysis showed the complete disappearance of the thrombosed aneurysm in 30% of cases and partial shrinkage in 52%; furthermore, thrombosed aneurysms were stable in 11% of cases and enlarged in 7%. CONCLUSIONS: The Silk stent is an effective tool for the treatment of challenging aneurysms because it allows complete occlusion in most cases 1 year after treatment. Permanent morbidity was 7.8%, and mortality was 3%.

Stent-assisted coiling of complex middle cerebral artery aneurysms: initial and midterm results.

Complex middle cerebral artery aneurysms are difficult to treat surgically or via endovascular approaches. Here, the authors treated 52 such lesions (41 aneurysms were unruptured and 11 had previously bled) via a combined approach that included stenting and coil embolization. They were able to coil 50 aneurysms after stent deployment and the most common immediate complication was intra-stent clot formation. At 14 months, follow-up showed 7 recurrences and 5 of these were re-treated. No aneurysm bled during this period of time and no intra-stent stenoses developed. The authors concluded that their technique is feasible, safe, and durable. BACKGROUND AND PURPOSE: Clinical outcome and initial and midterm angiographic results of EVT of complex MCA aneurysms by using the stent-assisted coiling technique were retrospectively evaluated in our center where EVT of intracranial aneurysms is the first treatment option. MATERIALS AND METHODS: From November 2003 to October 2009, 49 patients (27 men, 22 women; mean age, 52 ± 12 years) harboring 52 complex unruptured MCA aneurysms (11 ruptured previously and coiled but recanalized and 41 unruptured) were treated by EVT by using self-expandable intracranial stents. Procedural complications, clinical outcome, and initial and midterm angiographic results were evaluated. Initial treatment status and aneurysm sac size were tested as potential risk factors for recurrence. RESULTS: After successful stent deployment, coiling was performed in 50 aneurysms (96.2%) in 47 patients; however, 2 failures (3.8%) occurred in 2 patients. Ten intrastent clot formations (20%) observed on final control angiography induced 2 permanent moderate disabilities (GOS score = 2). Mortality and permanent neurologic morbidity were 0% and 4.3%, respectively. At a mean period of 14 ± 9 months, among 48 aneurysms in 45 patients eligible for follow-up, 34 complete (71%) and 14 partial treatments (29%) were observed, 7 recurrences (14.6%) occurred, and 5 patients (10.4%) needed retreatment. No aneurysm bleeding or symptomatic intrastent stenosis was observed. Aneurysm sac size ≥7 mm and incomplete initial treatment were associated with more recurrences without a statistically significant difference. CONCLUSIONS: For complex unruptured MCA aneurysms, EVT by using a self-expandable intracranial stent was feasible, safe, and durable and could be considered as the first-option treatment.

Endovascular Treatment of 174 Middle Cerebral Artery Aneurysms: Clinical Outcome and Radiologic Results at Long-term Follow-up

PURPOSE To retrospectively evaluate the immediate safety and efficacy as well as the clinical outcome and long-term angiographic results of endovascular treatment (EVT) of middle cerebral artery (MCA) aneurysms. MATERIALS AND METHODS This is a retrospective review of patients in whom coiling of MCA aneurysms was attempted over a 7-year period. Institutional review board approval and informed written consent were obtained. This study included 153 patients (90 women, 63 men; mean age, 49.5 years +/- 11.7 [standard deviation]) with 174 MCA aneurysms (71 unruptured, 103 ruptured). Complications of EVT, clinical outcome, and the results of either cerebral digital subtraction angiography (DSA) or magnetic resonance (MR) angiography were analyzed at initial, intermediate (6-18 months), and late (2-7 years) follow-up. RESULTS Coiling was performed in 160 (92%) aneurysms in 141 patients. Periprocedural complications were observed in 31 (19.4%) procedures, including aneurysm perforations (n = 7, 4.4%) and thromboembolic events (n = 24, 15.0%). EVT induced permanent morbidity in eight (5.7%) patients, with severe neurologic impairment in three (2.1%) and two deaths (1.4%). Of 114 MCA aneurysms controlled by using DSA (n = 50) or MR angiography (n = 64) at 50 months +/- 14, 73 (64%) remained completely occluded, 31 (27.2%) recurred, and 12 (10.5%) major recurrences were retreated. A balloon remodeling technique allowed treatment of complex aneurysms (n = 63) but was associated with more recurrences in the long term (42.6%) than aneurysms treated without balloon assistance (16.4%; P = .016). CONCLUSION EVT of MCA aneurysms was safe and long-term monitoring of patients showed a low rate of recurrence requiring retreatment. However, complex anatomy and long-term recurrences have to be addressed when considering EVT for MCA aneurysms.

Biomechanical wall properties of human intracranial aneurysms resected following surgical clipping (IRRAs Project)

BACKGROUND AND PURPOSE Individual rupture risk assessment of intracranial aneurysms is a major issue in the clinical management of asymptomatic aneurysms. Aneurysm rupture occurs when wall tension exceeds the strength limit of the wall tissue. At present, aneurysmal wall mechanics are poorly understood and thus, risk assessment involving mechanical properties is inexistent. Aneurysm computational hemodynamics studies make the assumption of rigid walls, an arguable simplification. We therefore aim to assess mechanical properties of ruptured and unruptured intracranial aneurysms in order to provide the foundation for future patient-specific aneurysmal risk assessment. This work also challenges some of the currently held hypotheses in computational flow hemodynamics research. METHODS A specific conservation protocol was applied to aneurysmal tissues following clipping and resection in order to preserve their mechanical properties. Sixteen intracranial aneurysms (11 female, 5 male) underwent mechanical uniaxial stress tests under physiological conditions, temperature, and saline isotonic solution. These represented 11 unruptured and 5 ruptured aneurysms. Stress/strain curves were then obtained for each sample, and a fitting algorithm was applied following a 3-parameter (C(10), C(01), C(11)) Mooney-Rivlin hyperelastic model. Each aneurysm was classified according to its biomechanical properties and (un)rupture status. RESULTS Tissue testing demonstrated three main tissue classes: Soft, Rigid, and Intermediate. All unruptured aneurysms presented a more Rigid tissue than ruptured or pre-ruptured aneurysms within each gender subgroup. Wall thickness was not correlated to aneurysmal status (ruptured/unruptured). An Intermediate subgroup of unruptured aneurysms with softer tissue characteristic was identified and correlated with multiple documented risk factors of rupture. CONCLUSION There is a significant modification in biomechanical properties between ruptured aneurysm, presenting a soft tissue and unruptured aneurysms, presenting a rigid material. This finding strongly supports the idea that a biomechanical risk factor based assessment should be utilized in the to improve the therapeutic decision making.

MRI-Based Score for Acute Basilar Artery Thrombosis

Background: Intra-arterial thrombolysis may reduce mortality in acute basilar artery (BA) occlusion. We wanted to identify an easy-to-use pre-treatment MR-based predictor of clinical outcome in patients with acute BA occlusion treated with IAT. Methods: We analyzed 16 patients with acute BA occlusion prospectively. Vascular risk factors, as well as National Institutes of Health Stroke Scale (NIHSS) and Glasgow Coma Scale (GCS) scores were recorded on admission, together with a 10-point semiquantitative score reflecting the number of acute ischaemic brain lesions on diffusion-weighted imaging. The recanalization grade was evaluated by angiography. The clinical outcome, using the modified Rankin scale (mRs), was measured 3 months later. Results: Risk factors, NIHSS and GCS scores, time from symptom onset to treatment, recanalization rate, outcome and outcome predictors (such as age, NIHSS and GCS scores) were comparable to other studies. Haemorrhagic transformation of infarction occurred in 2 patients (12.5%). We found that a high lesion score was an additional predictor of poor outcome (p = 0.026). Conclusions: In patients with acute BA occlusion, treated with intra-arterial recombinant tissue plasminogen activator, a high number of acute ischaemic lesions, based on diffusion-weighted imaging, is a predictor of poor clinical outcome.

Patient Selection for Stroke Endovascular Therapy— DWI-ASPECTS Thresholds Should Vary among Age Groups: Insights from the RECOST Study

BACKGROUND AND PURPOSE: The purpose of this study was to evaluate the benefits of endovascular intervention in large-vessel occlusion strokes, depending on age class. MATERIALS AND METHODS: A clinical management protocol including intravenous treatment and mechanical thrombectomy was instigated in our center in 2009 (Prognostic Factors Related to Clinical Outcome Following Thrombectomy in Ischemic Stroke [RECOST] study). All patients with acute ischemic stroke with an anterior circulation major-vessel occlusion who presented within 6 hours were evaluated with an initial MR imaging examination and were analyzed according to age subgroups (younger than 50 years, 50–59 years, 60–69 years, 70–79 years; 80 years or older). The mRS score at 3 months was the study end point. RESULTS: One hundred sixty-five patients were included in the analysis. The mean age was 67.4 years (range, 29–90 years). The mean baseline NIHSS score was 17.24 (range, 3–27). The mean DWI-derived ASPECTS was 6.4. Recanalization of TICI 2b/3 was achieved in 80%. At 3 months, 41.72% of patients had a good outcome, with a gradation of prognosis depending on the age subgroup and a clear cutoff at 70 years. Only 19% of patients older than 80 years had a good outcome at 3 months (mean ASPECTS = 7.4) with 28% for 70–79 years (mean ASPECTS = 6.8), but 58% for 60–69 years (mean ASPECTS = 6), 52% for 50–59 years (mean ASPECTS = 5.91), and 72% for younger than 50 years (mean ASPECTS = 6.31). In contrast, the mortality rate was 35% for 80 years and older, and 26% for 70–79 versus 5%–9% for younger than 70 years. CONCLUSIONS: The elderly may benefit from thrombectomy when their ischemic core volume is low in comparison with younger patients who still benefit from acute recanalization despite larger infarcts. Stroke volume thresholds should, therefore, be related and adjusted to the patients age group.

Mechanical Thrombectomy in Acute Ischemic Stroke: Catch Device

BACKGROUND AND PURPOSE: Mechanical thrombectomy presents today a promising alternative to traditional stroke therapies. Our aim with this study was to evaluate the safety and efficacy of the Catch mechanical thrombectomy device in the treatment of acute stroke and report the angiographic results and clinical outcomes. MATERIALS AND METHODS: We performed an analysis of 40 consecutive patients with ischemic stroke treated with the Catch device at our academic center. Forty patients were treated with the device: 25 with anterior circulation stroke and 15 with posterior circulation stroke. Thirty seven (92.5%) patients received an additional treatment to aid revascularization, including 36 patients treated with rtPA (mean dose of 35 mg). RESULTS: The mean age was 63.5 years (range, 31–82 years; 55% men). The median NIHSS score at presentation was 18 (range, 3–38). The mean symptom-to-procedure start time was 440 minutes (range, 150–2637 minutes). Recanalization (TIMI 2–3) was achieved in 26/40 (65%). Symptomatic hemorrhage occurred in 18%. Procedural complications occurred in 6 patients without clinical consequences: 4 clot fragmentations and 2 vasospasms. Data were missing for 4 patients at 90 days. Ninety-day mortality was 41%; good 90-day functional outcome (mRS, ≤ 2) was achieved by 39% (14/36). Good neurologic outcomes at 90 days were more frequent (56.5% versus 7.7%), and mortality rates were lower (30% versus 61.5%) with successful compared with unsuccessful recanalization. CONCLUSIONS: In our retrospective case series, the Catch device appears effective in achieving recanalization and improving 90-day outcome in patients with acute ischemic stroke.

L’angio-scanner cérébral multibarrette peut-il supplanter l’angiographie conventionnelle dans le diagnostic étiologique des hémorragies sous-arachnoïdiennes ?

Resume Objectif Evaluer la fiabilite de l’angioscanner cerebral (ASC) dans le bilan etiologique des hemorragies sous-arachnoidiennes non traumatiques. Materiel et methode Nous avons etudie de facon prospective 57 dossiers de patients hospitalises pour hemorragie meningee non traumatique. Dans tous les cas, un ASC centre sur le polygone de Willis a ete pratique, suivi d’une angiographie cerebrale numerisee (ACN). Nous avons compare les resultats obtenus en ASC aux resultats de l’ACN, consideree comme la methode de reference. Resultats Ce travail montre que l’ASC permet le diagnostic des anevrysmes intra-crâniens avec une specificite de 100 %, mais avec une sensibilite inferieure a 86 % et une valeur predictive negative de 65 %. Les anevrysmes non diagnostiques en ASC sont localises le plus souvent sur la carotide interne supra-caverneuse et leur taille est inferieure a 5 mm. De plus, l’ASC echoue dans le diagnostic des autres causes d’hemorragie meningee. Conclusion L’ASC peut donc etre considere comme l’examen etiologique de premiere intention des hemorragies meningees non traumatiques, mais il doit imperativement etre complete par une exploration angiographique conventionnelle bien conduite, incluant des aquisitions tri-dimensionnelles, dans tous les cas ou il ne revele pas la cause de l’hemorragie.

Neuroradiological findings expand the phenotype of OPA1-related mitochondrial dysfunction

OBJECTIVE OPA1 mutations are responsible for more than half of autosomal dominant optic atrophy (ADOA), a blinding disease affecting the retinal ganglion neurons. In most patients the clinical presentation is restricted to the optic nerve degeneration, albeit in 20% of them, additional neuro-sensorial symptoms might be associated to the loss of vision, as frequently encountered in mitochondrial diseases. This study describes clinical and neuroradiological features of OPA1 patients. METHODS Twenty two patients from 17 families with decreased visual acuity related to optic atrophy and carrying an OPA1 mutation were enrolled. Patients underwent neuro-ophthalmological examinations. Brain magnetic resonance imaging (T1, T2 and flair sequences) was performed on a 1.5-Tesla MR Unit. Twenty patients underwent 2-D proton spectroscopic imaging. RESULTS Brain imaging disclosed abnormalities in 12 patients. Cerebellar atrophy mainly involving the vermis was observed in almost a quarter of the patients; other abnormalities included unspecific white matter hypersignal, hemispheric cortical atrophy, and lactate peak. Neurological examination disclosed one patient with a transient right hand motor deficit and ENT examination revealed hearing impairment in 6 patients. Patients with abnormal MRI were characterized by: (i) an older age (ii) more severe visual impairment with chronic visual acuity deterioration, and (iii) more frequent associated deafness. CONCLUSIONS Our results demonstrate that brain imaging abnormalities are common in OPA1 patients, even in those with normal neurological examination. Lactate peak, cerebellar and cortical atrophies are consistent with the mitochondrial dysfunction related to OPA1 mutations and might result from widespread neuronal degeneration.

Intracranial Aneurysmal Pulsatility as a New Individual Criterion for Rupture Risk Evaluation: Biomechanical and Numeric Approach (IRRAs Project)

BACKGROUND AND PURPOSE: The present study follows an experimental work based on the characterization of the biomechanical behavior of the aneurysmal wall and a numerical study where a significant difference in term of volume variation between ruptured and unruptured aneurysm was observed in a specific case. Our study was designed to highlight by means of numeric simulations the correlation between aneurysm sac pulsatility and the risk of rupture through the mechanical properties of the wall. MATERIALS AND METHODS: In accordance with previous work suggesting a correlation between the risk of rupture and the material properties of cerebral aneurysms, 12 fluid-structure interaction computations were performed on 12 “patient-specific” cases, corresponding to typical shapes and locations of cerebral aneurysms. The variations of the aneurysmal volume during the cardiac cycle (ΔV) are compared by using wall material characteristics of either degraded or nondegraded tissues. RESULTS: Aneurysms were located on 6 different arteries: middle cerebral artery (4), anterior cerebral artery (3), internal carotid artery (1), vertebral artery (1), ophthalmic artery (1), and basilar artery (1). Aneurysms presented different shapes (uniform or multilobulated) and diastolic volumes (from 18 to 392 mm3). The pulsatility (ΔV/V) was significantly larger for a soft aneurysmal material (average of 26%) than for a stiff material (average of 4%). The difference between ΔV, for each condition, was statistically significant: P = .005. CONCLUSIONS: The difference in aneurysmal pulsatility as highlighted in this work might be a relevant patient-specific predictor of aneurysm risk of rupture.