Preventive treatment of unruptured intracranial aneurysms in adult patients with sickle cell anemia: A cohort study.

BACKGROUND AND PURPOSE: Intracranial aneurysms are frequent in patients with sickle cell anemia, while subarachnoid hemorrhage is a major cause of death and disability in young adult patients. Several characteristics, such as younger age and smaller size at rupture, may incline therapeutic decision towards exclusion treatments. Clinical guidelines on treatment of unruptured intracranial aneurysms in this population are still missing. We aimed to assess the safety and efficacy of the treatment of unruptured intracranial aneurysm in patients with sickle cell anemia, using an adapted hematological preparation regimen. PATIENTS AND METHODS: Adult patients with sickle cell anemia and treated unruptured aneurysms by endovascular therapy or neurosurgery were included in this retrospective cohort study. Treatment decision was reached after multi-disciplinary assessment. A pre-operative blood transfusion protocol was undertaken targeting a HbS below 30%. Demographic data, hematological preparation parameters and clinical and radiological outcomes were documented. RESULTS AND CONCLUSIONS: Twenty-five procedures were performed in 18 patients encompassing 19 aneurysms treated by embolization and 6 by surgery. Median age at treatment was 34 years-old and median aneurysm dome size was 4.4 mm. Immediate aneurysm exclusion rate was 85.7% after endovascular therapy and 100% after neurosurgery. Median follow-up was 6 months, with all patients being asymptomatic at last follow-up. Two transitory ischemic neurological deficits, as well as four cases of iodine-induced encephalopathy were identified after embolization. No complication occurred after surgery. Endovascular therapy by coiling and neurosurgical treatment of unruptured intracranial aneurysms appears to be safe in patients with sickle cell anemia and should be considered given the specific hemorrhagic risk observed in this population. A rigorous hematological preparation, associated with a dedicated peri­operative protocol and an adequate therapeutic strategy are essential prerequisites.

Should posterior cerebral artery occlusions be recanalized? Insights from the Trevo Registry.

BACKGROUND AND PURPOSE: The purpose of this study was to evaluate the safety and effectiveness of mechanical thrombectomy (MT) in patients with acute ischaemic stroke related to isolated and primary posterior cerebral artery (PCA) occlusions amongst the patients enrolled in the multicentre post-market Trevo Registry. METHOD: Amongst the 2008 patients enrolled in the Trevo Registry with acute ischaemic stroke due to large vessel occlusion treated by MT, 22 patients (1.1%) [10 females (45.5%), mean age 66.2 ± 14.3 years (range 28-91)] had a PCA occlusion [17 P1 (77.3%) and five P2 occlusions (22.7%)]. Recanalization after the first Trevo (Stryker, Fremont, CA, USA) pass and at the end of the procedure was rated using the modified Thrombolysis in Cerebral Infarction (mTICI) score. Procedure-related complications (i.e. groin puncture complication, perforation, symptomatic haemorrhage, embolus in a new territory) were also recorded. The modified Rankin Scale at 90 days was assessed. RESULTS: Median National Institutes of Health Stroke Scale at admission was 14 (interquartile range 8-16). Stroke aetiology was cardio-embolic in 68.2% of cases. Half of the patients (11/22) received intravenous tissue plasminogen activator. 54.5% of the patients were treated under general anaesthesia. Reperfusion (i.e. mTICI 2b or 3) after first pass was obtained in 65% of cases. Final mTICI 2b-3 reperfusion was obtained in all cases. Only one (4.5%) procedure-related complication was recorded (puncture site) that resolved after surgery. At 90-day follow-up, modified Rankin Scale 0-2 was obtained in 59% of the patients and 9.1% died within the first 3 months after MT. CONCLUSION: Mechanical thrombectomy for PCA occlusions seems to be safe (<5% procedure-related complications) and effective. Larger repository datasets are needed.

Endovascular treatment of brain arteriovenous malformations using a liquid embolic agent: results of a prospective, multicentre study (BRAVO).

OBJECTIVES: To evaluate the safety and efficacy of a new liquid embolic agent in brain arteriovenous malformation (bAVMs) embolisation. METHODS: A prospective, multicentre series was conducted at 11 interventional centres in Europe to evaluate embolisation of bAVMs with the new liquid embolic agent. Technical conditions, complications, clinical outcome and anatomical results were independently analysed. RESULTS: From December 2005 to December 2008, 117 patients (72 male; 45 female, aged 18-75 years) were included. Clinical presentation was mostly haemorrhage (34.2 %) and seizures (28.2 %). Most AVMs were located in the brain hemispheres (85.5 %). AVMs were <3 cm in 52.1 % of patients and ≥ 3 cm in 47.9 %. Morbidity was observed in 6/117 patients (5.1 %), related to haemorrhagic events in 2 cases and non-haemorrhagic complications in 4 cases. Five patients (4.3 %) died in relation to the treatment (bleeding in 4 patients and extensive venous thrombosis in 1). Complete occlusion of the AVM by embolisation alone was obtained in 23.5 % of patients. Complementary treatment was performed in 82.3 % of patients with partial AVM occlusion, mostly radiosurgery. CONCLUSIONS: In this prospective, multicentre, European, observational series, the new liquid embolic agent proved to be suitable for BAVM embolisation, with acceptable morbidity and mortality and good efficacy. KEY POINTS: • Numerous interventional techniques have been used to embolise brain arteriovenous malformations (AVMs). • This prospective multicentre study demonstrates the suitability of a liquid embolic agent. • The safety of treatment using Onyx is acceptable. • Such embolisation leads to complete AVM occlusion in 23.5 % of patients.

Direct Aspiration versus Combined Technique for Distal Medium-Vessel Occlusions: Comparison on a Human Placenta Model.

BACKGROUND AND PURPOSE: Mechanical thrombectomy appears to be a promising option for distal medium-vessel occlusions, for which intravenous thrombolysis is effective but may be insufficient when used alone. This study aimed to determine the optimal technique for these distal mechanical thrombectomies using the human placenta model. MATERIALS AND METHODS: Twenty-four procedures were performed, allowing comparison of direct aspiration (n = 12) versus the combined technique (n = 12). Two positions of the aspiration catheter were tested for each of these techniques: in direct contact with the clot and at a distance from it (5-10 mm). Two types of clots were tested: red blood cell-rich clots and fibrin-rich clots. First-pass recanalization and induced arterial collapse and traction were assessed. RESULTS: The first-pass recanalization was less frequent for direct aspiration than for the combined technique, without reaching statistical significance (41.7% versus 75.0%, P = .098). Full collapse (P < .001) and extended arterial traction (P = .001) were significantly less frequent for direct aspiration. For direct aspiration with the aspiration catheter not in direct contact with the clot, there was not a single first-pass recanalization and there was systematic arterial collapse, resulting in a no-flow in the aspiration syringe. CONCLUSIONS: The combined technique appears to be more harmful, and although direct aspiration has a lower rate of first-pass recanalization, it seems appropriate to try direct aspiration as a first-line procedure. However, if the aspiration catheter cannot reach the clot, it is not useful or even risky to try aspiration alone. These results need to be confirmed by clinical studies.

N-terminal pro-B-type natriuretic peptide for prediction of ventricular arrhythmias: Data from the SMASH study.

BACKGROUND: Elevated N-terminal pro-B-type natriuretic peptide (NT-proBNP) concentrations predict heart failure (HF) and mortality, but whether NT-proBNP predicts ventricular arrhythmias (VA) is not clear. HYPOTHESIS: We hypothesize that high NT-proBNP concentrations associate with the risk of incident VA, defined as adjudicated ventricular fibrillation or sustained ventricular tachycardia. METHODS: In a prospective, observational study of patients treated with implantable cardioverter defibrillator (ICD), we analyzed NT-proBNP concentrations at baseline and after mean 1.4 years in association to incident VA. RESULTS: We included 490 patients (age 66 ± 12 years, 83% men) out of whom 51% had a primary prevention ICD indication. The median NT-proBNP concentration was 567 (25-75 percentile 203-1480) ng/L and patients with higher concentrations were older with more HF and ICD for primary prevention. During mean 3.1 ± 0.7 years, 137 patients (28%) had ≥1 VA. Baseline NT-proBNP concentrations were associated with the risk of incident VA (hazard ratio [HR]: 1.39, 95% confidence interval [95% CI]: 1.22-1.58, p < .001), HF hospitalizations (HR: 3.11, 95% CI: 2.53-3.82, p < .001), and all-cause mortality (HR: 2.49, 95% CI: 2.04-3.03, p < .001), which persisted after adjusting for age, sex, body mass index, coronary artery disease, HF, renal function, and left ventricular ejection fraction. The association with VA was stronger in secondary versus primary prevention ICD indication: HR: 1.59 (95% CI: 1.34-1.88 C-statistics 0.71) versus HR: 1.24, 95% CI: 1.02-1.51, C-statistics 0.55), p-for-interaction = 0.06. Changes in NT-proBNP during the first 1.4 years did not associate with subsequent VA. CONCLUSIONS: NT-proBNP concentrations are associated with the risk of incident VA after adjustment for established risk factors, with the strongest association in patients with a secondary prevention ICD indication.

Persistent trigeminal artery feeding a hemispheric branch of the posterior inferior cerebellar artery: a rare anatomic variant.

Persistent trigeminal artery is a rare persistent carotid-basilar anastomosis that usually connect the infracavernous segment of the ICA with the basilar artery. Rarely, PTA may feed cerebellar artery. We describe an exceptional case of PTA terminating in postero-inferior cerebellar artery (PICA) hemispheric branch. Angiographic and CTA features are presented and hypotheses regarding developmental origin of this variation are discussed.

Pressure Cooker Technique for Endovascular Treatment of Spinal Arteriovenous Fistulas: Experience in 15 Cases.

BACKGROUND AND PURPOSE: Spinal arteriovenous fistulas are challenging to cure by endovascular means, with a risk of incomplete occlusion or delayed recurrence. The authors report herein their preliminary experience using the pressure cooker technique for the embolization of spinal arteriovenous fistulas. MATERIALS AND METHODS: Fifteen patients (8 men; mean age, 60.3 years) underwent an endovascular treatment of a spinal arteriovenous fistula (12 dural spinal arteriovenous fistulas and 3 epidural spinal arteriovenous fistulas) in 2 different institutions using the pressure cooker technique. Two microcatheters could be navigated in the segmental artery in all patients using 2 guiding catheters. A proximal plug was achieved with highly concentrated cyanoacrylate ± coils. The liquid embolic agent injected to cure the fistula was diluted cyanoacrylate (n = 11) or ethylene-vinyl alcohol (n = 4). Technical and clinical complications were systematically recorded. Clinical and angiographic outcomes were systematically evaluated at follow-up. RESULTS: One (6.7%) procedure-related complication was recorded, which consisted of a transient radicular deficit, related to nerve root ischemia. Clinical improvement was observed in 10/14 (71%) patients for whom clinical follow-up was available. Complete spinal arteriovenous fistula occlusion on a follow-up angiography was observed in 11/12 patients (91.7%) for whom angiographic follow-up was available. One patient (8.3%) presented with a delayed recurrence at 29 months. CONCLUSIONS: The pressure cooker technique is feasible, with either glue or ethylene-vinyl alcohol, for the embolization of spinal arteriovenous fistulas. Our results suggest the safety and effectiveness of this technique.

CTA-Based Patient-Tailored Femoral or Radial Frontline Access Reduces the Rate of Catheterization Failure in Chronic Subdural Hematoma Embolization.

BACKGROUND AND PURPOSE: Chronic subdural hematoma embolization, an apparently simple procedure, can prove to be challenging because of the advanced age of the target population. The aim of this study was to compare 2 arterial-access strategies, femoral versus patient-tailored CTA-based frontline access selection, in chronic subdural hematoma embolization procedures. MATERIALS AND METHODS: This was a monocentric retrospective study. From the March 15, 2018, to the February 14, 2019 (period 1), frontline femoral access was used. Between February 15, 2019, and March 30, 2020 (period 2), the choice of the frontline access, femoral or radial, was based on the CTA recommended as part of the preoperative work-up during both above-mentioned periods. The primary end point was the rate of catheterization failure. The secondary end points were the rate of access site conversion and fluoroscopy duration. RESULTS: During the study period, 124 patients (with 143 chronic subdural hematomas) underwent an embolization procedure (mean age, 74 [SD, 13] years). Forty-eight chronic subdural hematomas (43 patients) were included during period 1 and were compared with 95 chronic subdural hematomas (81 patients) during period 2. During the first period, 5/48 (10%) chronic subdural hematoma embolizations were aborted due to failed catheterization, significantly more than during period 2 (1/95, 1%; P = .009). The rates of femoral-to-radial (P = .55) and total conversion (P = .86) did not differ between the 2 periods. No significant difference was found regarding the duration of fluoroscopy (P = .62). CONCLUSIONS: A CTA-based patient-tailored choice of frontline arterial access reduces the rate of catheterization failure in chronic subdural hematoma embolization procedures.

Risk Factors for Early Brain AVM Rupture: Cohort Study of Pediatric and Adult Patients.

BACKGROUND AND PURPOSE: Whether architectural characteristics of ruptured brain AVMs vary across the life span is unknown. We aimed to identify angioarchitectural features associated with brain AVMs ruptured early in life. MATERIALS AND METHODS: Patients with ruptured brain AVMs referred to 2 distinct academic centers between 2000 and 2018 were pooled and retrospectively analyzed. Imaging was retrospectively reviewed for angioarchitectural characteristics, including nidus size, location, Spetzler-Martin grade, venous drainage, and arterial or nidal aneurysm. Angioarchitecture variations across age groups were analyzed using uni- and multivariable models; then cohorts were pooled and analyzed using Kaplan-Meier and Cox models to determine factors associated with earlier rupture. RESULTS: Among 320 included patients, 122 children (mean age, 9.8 ± 3.8 years) and 198 adults (mean age, 43.3 ± 15.7 years) were analyzed. Pediatric brain AVMs were more frequently deeply located (56.3% versus 21.2%, P < .001), with a larger nidus (24.2 versus 18.9 mm, P = .002), were less frequently nidal (15.9% versus 23.5%, P = .03) and arterial aneurysms (2.7% versus 17.9%, P < .001), and had similar drainage patterns or Spetzler-Martin grades. In the fully adjusted Cox model, supratentorial, deep brain AVM locations (adjusted relative risk, 1.19; 95% CI, 1.01-1.41; P = .03 and adjusted relative risk, 1.43; 95% CI, 1.22-1.67; P < .001, respectively) and exclusively deep venous drainage (adjusted relative risk, 1.46, 95% CI, 1.21-1.76; P < .001) were associated with earlier rupture, whereas arterial or nidal aneurysms were associated with rupture later in life. CONCLUSIONS: The angioarchitecture of ruptured brain AVMs significantly varies across the life span. These distinct features may help to guide treatment decisions for patients with unruptured AVMs.

Endovascular treatment of brain arteriovenous malformations using onyx: results of a prospective, multicenter study.

BACKGROUND AND PURPOSE: To evaluate the safety and efficacy of onyx for embolization of brain arteriovenous malformations (BAVM). METHODS: A prospective, multicenter study was conducted in France to evaluate embolization of BAVM with onyx. From May 2003 to March 2005, 50 patients (26 females, 24 males; mean age: 34.8 years, range: 16-64years) were included. Clinical presentation was haemorrhage in 22 patients (44.0%), seizures in 16 patients (32.0%), headaches in six patients (12.0%) and progressive neurological deficit in two cases (4.0%). Four patients were asymptomatic (8.0%). RESULTS: One hundred and forty-ninesessions of embolization were performed: one to eight sessions/patient with a mean of 3.0sessions. One hundred and sixteen sessions (77.9%) were performed with onyx, 20 sessions (13.4%) with glue and 13 sessions (8.7%) with onyx and glue. Symptomatic acute postembolization haemorrhage (APEH) was observed in four cases (8.0% per patient). At 1 month, morbidity and mortality related to the treatment were of 8% and 2%, respectively. Complete BAVM occlusion was obtained in 8.3% of cases. In the remaining cases, occlusion rate was between 99 and 80% in 56.3% of patients, 79 and 60% in 16.7%, and less than 60 in 18.7%. In case of incomplete occlusion, complementary treatment was performed by radiosurgery. CONCLUSION: Onyx is suitable for BAVM embolization with acceptable morbidity and mortality.

Flow Diverter Stents for the Treatment of Anterior Cerebral Artery Aneurysms: Safety and Effectiveness.

BACKGROUND AND PURPOSE: Flow diverter stents (FDSs) are increasingly used for the treatment of intracranial aneurysms. Initially developed for the management of giant and large aneurysms, their indications have progressively expanded. The purpose of our study was to evaluate the safety and effectiveness of FDSs for the treatment of anterior cerebral artery (ACA) aneurysms. MATERIALS AND METHODS: Among the 94 consecutive patients treated for 100 intracranial aneurysms by means of FDSs in our institution from October 2010 to January 2015, eight aneurysms (8 %) in seven patients were located on the ACA. Three aneurysms were located on the A1 segment, three aneurysms on the anterior communicating artery (ACom) and two on the A2-A3 junction. In three cases, FDS was used for angiographic recurrence after coiling. Five patients were treated with a Pipeline embolization device, one with a NeuroEndograft and the last one with a Silk FDS. RESULTS: Treatment was feasible in all cases. No technical difficulty was reported. No acute or delayed clinical complication was recorded. Modified Rankin Scale was 0 for six patients and one for one patient. Mean angiographic follow-up was 9.7 ± 3.9 months (range 6-15). Total exclusion was observed in five aneurysms (71.4 %) and neck remnant in two (28.6 %) cases. One patient refused the control DSA. CONCLUSION: Our series shows the safety and effectiveness of FDSs for the treatment of ACA aneurysms.

Clinical Impact of Flat Panel Volume CT Angiography in Evaluating the Accurate Intraoperative Deployment of Flow-Diverter Stents.

BACKGROUND AND PURPOSE: The deployment of flow-diverter stents may be difficult to analyse on regular DSA. The purpose of our study was to investigate the clinical impact of stent-dedicated flat panel volume CT angiography to evaluate intraoperatively the satisfactory deployment of flow-diverter stents. MATERIALS AND METHODS: From January 2009 to April 2015, 83 consecutive patients (mean age, 51 years; 62 women) were treated in our institution with flow-diverter stents. Eighty-seven aneurysms (82 unruptured, 5 ruptured; 77 anterior, 10 posterior circulation) were treated in these 83 patients (4 patients had 2 aneurysms, both treated by means of flow-diverter stents). One patient was treated for a traumatic carotid cavernous fistula. In 80% of the cases (68/85) a flat panel volume CT angiography was performed in the angiographic suite just after the flow-diverter stent deployment. Stent visualization was assessed by 2 independent reviewers. The clinical impact of stent malapposition was evaluated. RESULTS: Flow-diverter stent visualization was satisfactory in 73.5% of the cases. In 2 cases (2.9%) the flat panel volume CT angiography prompted the operator to perform an additional intrastent angioplasty for a condition that was previously underestimated. Four patients (4.7%) experienced acute thromboembolic complications; 3 others had delayed thromboembolic complications. Only 1 of these patients had thromboembolic complications (acute or delayed) related to stent misdeployment, which was easily managed intraoperatively with no clinical consequence. CONCLUSIONS: Flat panel volume CT angiography is an interesting tool to depict flow-diverter stent misdeployment and may encourage the operator to perform intrastent angioplasty (2.9% of the cases in our experience) to reduce the risks of thromboembolic complications.

Retrospective Analysis of Delayed Intraparenchymal Hemorrhage after Flow-Diverter Treatment: Presentation of a Retrospective Multicenter Trial.

BACKGROUND AND PURPOSE: Intracranial aneurysm treatment with flow diverters has shown satisfying results in terms of aneurysm occlusion, and while some cases of delayed intraparenchymal hemorrhage have been described, no systematic analysis of the risk factors affecting its occurrence has been conducted in a large series of patients. This retrospective analysis of delayed intraparenchymal hemorrhage after flow-diverter treatment is a multicenter, retrospective study using a large series of treated patients to analyze factors affecting the occurrence of delayed intraparenchymal hemorrhage. MATERIALS AND METHODS: Patients treated with flow diverters and presenting with delayed intraparenchymal hemorrhage were included from December 2007 to December 2014 in 7 participating centers in France. Patient and aneurysm characteristics were recorded as were characteristics of bleeding (size, lateralization, and time to bleed), treatment, and clinical outcome after 1, 3, and 6 months. RESULTS: Delayed intraparenchymal hemorrhage occurred in 11 patients between 1 and 21 days after the procedure. In 10 of these patients, hemorrhages were ipsilateral to the treated aneurysms. Five of the 11 underwent surgery, and 9 of the 11 had good clinical outcomes at 6 months (mRS ≤2). CONCLUSIONS: The pathogenesis of delayed intraparenchymal hemorrhage occurring after flow-diverter treatment remains unclear. The multidisciplinary management of delayed intraparenchymal hemorrhage yields a relatively low morbidity-mortality rate compared with the initial clinical presentation.

Flow Diversion versus Standard Endovascular Techniques for the Treatment of Unruptured Carotid-Ophthalmic Aneurysms.

BACKGROUND AND PURPOSE: Over the past few years, flow diversion has been increasingly adopted for the treatment of intracranial aneurysms, especially in the paraclinoid and paraophthalmic carotid segment. We compared clinical and angiographic outcomes and complication rates in 2 groups of patients with unruptured carotid-ophthalmic aneurysms treated for 7 years by either standard coil-based techniques or flow diversion. MATERIALS AND METHODS: From February 2006 to December 2013, 162 unruptured carotid-ophthalmic aneurysms were treated endovascularly in 138 patients. Sixty-seven aneurysms were treated by coil-based techniques in 61 patients. Flow diverters were deployed in 95 unruptured aneurysms (77 patients), with additional coiling in 27 patients. Complication rates, clinical outcome, and immediate and long-term angiographic results were retrospectively analyzed. RESULTS: No procedure-related deaths occurred. Four procedure-related thromboembolic events (6.6%) leading to permanent morbidity in 1 case (1.6%) occurred in the coiling group. Neurologic complications were observed in 6 patients (7.8%) in the flow-diversion group, resulting in 3.9% permanent morbidity. No statistically significant difference was found between complication (P = .9) and morbidity rates (P = .6). In the coiling group (median follow-up, 31.5 ± 24.5 months), recanalization occurred at 1 year in 23/50 (54%) aneurysms and 27/55 aneurysms (50.9%) at the latest follow-up, leading to retreatment in 6 patients (9%). In the flow-diversion group (mean follow-up, 13.5 ± 10.8 months), 85.3% (35/41) of all aneurysms were occluded after 12 months, and 74.6% (50/67) on latest follow-up. The retreatment rate was 2.1%. Occlusion rates between the 2 groups differed significantly at 12 months (P < .001) and at the latest follow-up (P < .005). CONCLUSIONS: Our retrospective analysis shows better long-term occlusion of carotid-ophthalmic aneurysms after use of flow diverters compared with standard coil-based techniques, without significant differences in permanent morbidity.

Surpass flow diverter in the treatment of intracranial aneurysms: a prospective multicenter study.

BACKGROUND AND PURPOSE: Incomplete occlusion and recanalization of large and wide-neck brain aneurysms treated by endovascular therapy remains a challenge. We present preliminary clinical and angiographic results of an experimentally optimized Surpass flow diverter for treatment of intracranial aneurysms in a prospective, multicenter, nonrandomized, single-arm study. MATERIALS AND METHODS: At 24 centers, 165 patients with 190 intracranial aneurysms of the anterior and posterior circulations were enrolled. The primary efficacy end point was the percentage of intracranial aneurysms with 100% occlusion on 6-month DSA. The primary safety end point was neurologic death and any stroke through a minimum follow-up of 6 months. RESULTS: Successful flow-diverter delivery was achieved in 161 patients with 186 aneurysms (98%); the mean number of devices used per aneurysm was 1.05. Clinical follow-up (median, 6 months) of 150 patients (93.2%), showed that the primary safety end point occurred in 18 subjects. Permanent neurologic morbidity and mortality were 6% and 2.7%, respectively. Morbidity occurred in 4% and 7.4% of patients treated for aneurysms of the anterior and posterior circulation, respectively. Neurologic death during follow-up was observed in 1.6% and 7.4% of patients with treated intracranial aneurysms of the anterior and posterior circulation, respectively. Ischemic stroke at ≤30 days, SAH at ≤7 days, and intraparenchymal hemorrhage at ≤7 days were encountered in 3.7%, 2.5%, and 2.5% of subjects, respectively. No disabling ischemic strokes at >30 days or SAH at >7 days occurred. New or worsening cranial nerve deficit was observed in 2.7%. Follow-up angiography available in 158 (86.8%) intracranial aneurysms showed 100% occlusion in 75%. CONCLUSIONS: Clinical outcomes of the Surpass flow diverter in the treatment of intracranial aneurysms show a safety profile that is comparable with that of stent-assisted coil embolization. Angiographic results showed a high rate of intracranial aneurysm occlusion.

MR determination of hippocampal volume: comparison of three methods.

PURPOSE: To determine whether measurements of the volume of the hippocampal formation obtained from a three-dimensional acquisition not perpendicular to the hippocampus are statistically different from those obtained from a perpendicular acquisition. METHODS: Both hippocampi were studied in 10 healthy volunteers with two three-dimensional acquisitions, allowing three different volume-calculation protocols: (a) on sections from a coronal 3-D acquisition not perpendicular to the axis of the hippocampal formation (NOPERP protocol), (b) on sections obtained with the same acquisition but reformatted perpendicular to the axis of the hippocampal formation (REFOR protocol), and (c) on sections from a coronal 3-D acquisition perpendicular to the axis of the hippocampal formation (PERP protocol) obtained with the patient's head tilted backward. To obtain measurements of the volume of the hippocampal formations, an accurate 3-D processing technique was used to segment the hippocampus. In all subjects, two hippocampal formation right-left asymmetry indexes were calculated by using each of the three protocols. RESULTS: For the right hippocampus, the mean volume was 3.42 cm3 (NOPERP protocol), 4.18 cm3 (REFOR protocol), and 3.91 cm3 (PERP protocol). For the left hippocampus, the mean volume was 3.29 cm3 (NOPERP protocol), 4.02 cm3 (REFOR protocol), and 3.74 cm3 (PERP protocol). For both hippocampi, the differences of the mean volumes were significant between each protocol. However, for both hippocampi, a high correlation was observed between volumes obtained with the different protocols. For the two asymmetry indexes, there were no significant differences for the means obtained with the three protocols. CONCLUSION: With the use of 3-D acquisitions in the study of hippocampal formation biometry, different procedures lead to significant variations in the absolute values of the volume of the hippocampal formation. However, there is a strong correlation between the results obtained by each method.

Cerebral aneurysms treated by Guglielmi detachable coils: evaluation with diffusion-weighted MR imaging.

BACKGROUND AND PURPOSE: The most frequent and serious complications of endovascular treatment of intracranial aneurysms with Guglielmi detachable coils (GDCs) are ischemic lesions caused by thromboembolic events. Diffusion-weighted MR imaging appears to be the most sensitive technique for detecting early ischemic phenomena. We evaluated this technique for the detection of brain changes in patients who underwent GDC treatment of aneurysms. METHODS: Twenty patients with a cerebral aneurysm were studied with diffusion-weighted imaging before and after endovascular treatment with GDCs. Aneurysms were located in the anterior (n = 16) or posterior (n = 4) circulation. Bleeding had occurred in 11 patients. MR studies, including fast fluid-attenuated inversion recovery (FLAIR) and diffusion-weighted sequences, were scheduled before, 2 to 4 hours after, and 48 hours after treatment. MR images, including apparent diffusion coefficient (ADC) maps, were assessed for the presence of acute ischemic stroke lesions. RESULTS: In all patients, the aneurysm was excluded without neurologic worsening. In 18 patients, diffusion-weighted and FLAIR images showed no evidence of recent ischemic lesions after treatment. In one patient, an asymptomatic frontobasal hyperintense signal on diffusion-weighted images with a drop of ADC values corresponding to an acute ischemic lesion was observed. In another patient, multiple silent lesions were seen on diffusion-weighted images after embolization. These silent lesions were not all located in the vascular territory of the aneurysm's parent artery. CONCLUSION: This preliminary study suggests that diffusion-weighted MR imaging is a potentially useful tool for monitoring patients after endovascular treatment of a cerebral aneurysm. While small asymptomatic lesions can be observed on these images after embolization, their exact prevalence should be evaluated in a larger series.

[Exploration of the origin of supra-aortic arterial trunk: can MR angiography with gadolinium injection replace digital angiography?]. / Exploration de l'origine des troncs artériels supra-aortiques: l'angio-irm avec injection de gadolinium peut-elle remplacer l'angiographie numérisée?

Ostial stenosis of the craniocervical vessels are frequently associated with carotid stenosis. Consequently, exploration of the aortic arch is necessary prior to carotid endarterectomy. Contrast-enhanced MR angiography (gRMA) could replace digital substraction angiography (DSA). The goal of this work was to evaluate gRMA for the detection of ostial stenosis of the craniocervical vessels. Twenty two patients with carotid stenosis > 50% on sonography examination prospectively underwent gRMA and DSA. We analyzed the overall quality of each gRMA and the degree of ostial stenosis of the craniocervical vessels (innominate, left carotid, subclavian and vertebral arteries). Thirteen gRMA examination was considered as good quality and 8 as adequate for diagnosis. There was significant correlation between gRMA and DSA for degree of stenosis (k = 0.82, p < 0.0001). gRMA tends to overestimate degree of ostial stenosis, especially for vertebral arteries. We conclude that gRMA is a promising tool but cannot yet be used as a stand-alone procedure for the evaluation of ostial stenosis of the craniocervical vessels.

[Evolution of angiographic signs of venous hypertension and clinical signs of intracranial hypertension in intracranial dural arteriovenous fistulas]. / Evolution après traitement endovasculaire des signes angiographiques d'hypertension veineuse et des signes cliniques d'hypertension intracrânienne dans les fistules artérioveineuses durales intracrâniennes.

Dural arteriovenous fistulas (dAVFs) can cause cerebral venous hypertension (VHT). The most common mechanism is due to the fact that some dAVFs can drain retrogradelly in cortical (better defined as leptomeningeal) veins (directly or after drainage in a dural sinus) causing venous engorgement and consequently an impairment of the cerebral venous drainage. However, more rarely, dAVFs without a cortical venous drainage can also be responsible for VHT probably due to dAVF shunts causing insufficient antegrade cerebral venous drainage. In addition, dAVFs are often associated with stenosis and/or thrombosis of dural sinus(es) which can worsen the VHT. Raised pressure within the superior sagittal sinus causes impeded cerebrospinal reabsorption in the arachnoid villi allowing increased intracranial pressure. The venous engorgement in the cortical veins can cause a venous congestive encephalopathy analogous to the venous congestive myelopathy of the spinal dural AVFs. Clinically VHT can cause not only symptoms related to increased intracranial pressure but also seizures, neurological deficits, impairment of the cognitive functions and dementia. An important aspect is the risk of hemorrhage in dAVFs with a leptomeningeal venous drainage leading to VHT. Although the term VHT sensu strictu should be used if venous pressure measurements are performed, angiographic criteria for VHT such as delayed circulation time, venous engorgement and abnormal visualization of the cerebral veins are well established. The purpose of our study was to evaluate the angiographic signs of VHT in patients with dAVF and to study the course of the VHT and of the clinical signs of increased intracranial pressure before and after dAVF endovascular treatment. A retrospective chart analysis of 22 patients (13 males, 9 females) ranging in age from 20 to 87 years (mean: 53 ys.) with a dAVF associated with angiographic signs of VHT was performed. Ten dAVFs were located on the transverse/sigmoid sinus(es), 6 on the superior sagittal sinus, 3 on the petro-tentorial incisura, 1 on the inferior petrosal sinus, 1 on the anterior ethmoidal region and 1 on the Galen vein region. All dAVFs had a retrograde leptomeningeal venous drainage. Stenosis or thrombosis of the dural AVF sinus was observed in 17 cases and stenosis or thrombosis of another sinus(es) and/or of the jugular vein in 8 cases. In 11 patients, the angiographic signs of VHT were global affecting the entire cerebral venous drainage and, in the other 11 patients, the VHT was focal. The VHT caused clinical symptoms of increased intracranial pressure in 18 patients. Other clinical findings included: bruit (11 cases), seizures (3 cases), vertigo (3 cases), visual deficits (2 cases) and impairment of cognitive functions (4 cases). Three patients presented hemorrhage (one parenchymal hematoma, one hemorrhagic infarction and one subarachnoid hemorrhage). The 4 patients without clinical symptoms of increased intracranial pressure presented only bruit in 2 cases, bruit and vertigo in 1 case, bruit and hemorrhagic infarction in another one. The dAVFs were treated by endovascular therapy (arterial approach: 3 cases, venous approach: 6 cases and both arterial and venous approach: 13 cases). Endovascular sessions ranged from 1 to 7 (mean: 2.8) for each patient. After the endovascular treatment, in 12 patients with complete occlusion of the dAVF, the disappearance of angiographic signs of VHT and clinical cure were observed. In 8 patients with partial occlusion of the dAVF, the disappearance of angiographic signs of VHT and clinical cure were observed in 4 cases (almost complete dAVF occlusion in 2 cases); in the other 4 cases, only reduction the angiographic signs of VHT and clinical improvement were obtained. In all 16 patients who were clinically cured angiographic signs of VHT disappeared despite the persistence of dAVF shunts as observed in 4 cases. (ABSTRACT TRUNCATED)