Antithrombotic regimen in emergent carotid stenting for acute ischemic stroke due to tandem occlusion: a meta-analysis of aggregate data.

BACKGROUND: The periprocedural antithrombotic regimen might affect the risk-benefit profile of emergent carotid artery stenting (eCAS) in patients with acute ischemic stroke (AIS) due to tandem lesions, especially after intravenous thrombolysis. We conducted a systematic review and meta-analysis to evaluate the safety and efficacy of antithrombotics following eCAS. METHODS: We followed PRISMA guidelines and searched MEDLINE, Embase, and Scopus from January 1, 2004 to November 30, 2022 for studies evaluating eCAS in tandem occlusion. The primary endpoint was 90-day good functional outcome. Secondary outcomes were symptomatic intracerebral hemorrhage, in-stent thrombosis, delayed stent thrombosis, and successful recanalization. Meta-analysis of proportions and meta-analysis of odds ratios were implemented. RESULTS: 34 studies with 1658 patients were included. We found that the use of no antiplatelets (noAPT), single antiplatelet (SAPT), dual antiplatelets (DAPT), or glycoprotein IIb/IIIa inhibitors (GPI) yielded similar rates of good functional outcomes, with a marginal benefit of GPI over SAPT (OR 1.88, 95% CI 1.05 to 3.35, Pheterogeneity=0.31). Sensitivity analysis and meta-regression excluded a significant impact of intravenous thrombolysis and Alberta Stroke Program Early CT Score (ASPECTS). We observed no increase in symptomatic intracerebral hemorrhage (sICH) with DAPT or GPI compared with noAPT or SAPT. We also found similar rates of delayed stent thrombosis across groups, with acute in-stent thrombosis showing marginal, non-significant benefits from GPI and DAPT over SAPT and noAPT. CONCLUSIONS: In AIS due to tandem occlusion, the periprocedural antithrombotic regimen of eCAS seems to have a marginal effect on good functional outcome. Overall, high intensity antithrombotic therapy may provide a marginal benefit on good functional outcome and carotid stent patency without a significant increase in risk of sICH.

Longitudinal radiological follow-up of individual level non-ischemic cerebral enhancing lesions following endovascular aneurysm treatment.

BACKGROUND: Non-ischemic cerebral enhancing (NICE) lesions following aneurysm endovascular therapy are exceptionally rare, with unknown longitudinal evolution. OBJECTIVE: To evaluate the radiological behavior of individual NICE lesions over time. METHODS: Patients included in a retrospective national multicentric inception cohort were analyzed. NICE lesions were defined, using MRI, as delayed onset punctate, nodular, or annular foci enhancements with peri-lesion edema, distributed in the vascular territory of the aneurysm treatment, with no other confounding disease. Lesion burden and the longitudinal behavior of individual lesions were assessed. RESULTS: Twenty-two patients were included, with a median initial lesion burden of 36 (IQR 17-54) on the first MRI scan. Of the 22 patients with at least one follow-up MRI scan, 16 (73%) had new lesions occurring mainly within the first 200 weeks after the date of the procedure. The median number of new lesions per MRI was 6 (IQR 2-16). Among the same 22 patients, 7 (32%) had recurrent lesions. The median persistent enhancement of a NICE lesion was 13 weeks (IQR 6-30). No factor was predictive of early regression of enhancement activity with lesion regression kinetics mainly being patient-dependent. CONCLUSIONS: The behavior of individual NICE lesions was found to be highly variable with an overall patient-dependent regression velocity.

Absorbable gelatin compressed sponge (Gelfoam) embolization of distal external carotid artery branches in intra-arterial chemotherapy for retinoblastoma.

BACKGROUND: In intra-arterial chemotherapy for retinoblastoma, a backflow from unreachable external carotid artery branches in the ophthalmic artery can be challenging. OBJECTIVE: To describe a new endovascular technique using Gelfoam pledgets to temporarily occlude distal branches of the external carotid artery to reverse the competitive backflow into the ophthalmic artery in order to perform intra-arterial chemotherapy via the ostium of the ophthalmic artery in selected cases. METHODS: We queried our prospectively collected database of 327 consecutive patients treated for retinoblastoma by intra-arterial chemotherapy and identified those employing Gelfoam pledgets. We describe this new technique with emphasis on feasibility and safety. RESULTS: We treated 11 eyes with 14 infusions of intra-arterial chemotherapy using Gelfoam pledgets to occlude the distal branches of the external carotid artery. We report no perioperative complications due to this occlusion technique. At the ophthalmologic follow-up 1 month after the injection of Gelfoam pledgets, all cases showed tumor regression or stable disease. Two injections into the same eye as the rescue intra-arterial chemotherapy infusion resulted in a transient exudative retinal detachment, and one injection in a heavily pretreated case was followed by iris neovascularization and retinal ischemia. None of the pledget injections led to irreversible vision-threatening intraocular complications. CONCLUSIONS: Intra-arterial chemotherapy in retinoblastoma using Gelfoam to transiently occlude the distal branches of the external carotid artery and reverse the backflow into the ophthalmic artery seems feasible and safe. Larges series will help to confirm the effectiveness of this new technique.

Delayed Functional Independence After Neurothrombectomy (DEFIANT) score: analysis of the Trevo Retriever Registry.

BACKGROUND: Chronological heterogeneity in neurological improvement after endovascular thrombectomy (EVT) for large vessel occlusion (LVO) stroke is commonly observed in clinical practice. Understanding the temporal progression of functional independence after EVT, especially delayed functional independence in patients who do not improve early, is essential for prognostication and rehabilitation. We aim to determine the incidence of early functional independence (EFI) and delayed functional independence (DFI), identify associated predictors after EVT, and develop the Delayed Functional Independence After Neurothrombectomy (DEFIANT) score. METHODS: Demographic, clinical, radiological, treatment, and procedural information were analyzed from the Trevo Registry (patients undergoing EVT due to anterior LVO using the Trevo stent retriever). Incidence and predictors of EFI (modified Rankin Scale (mRS) score 0-2 at discharge) and DFI (mRS score 0-2 at 90 days in non-EFI patients) were analyzed. RESULTS: A total of 1623 patients met study criteria. EFI was observed in 45% (730) of patients. Among surviving non-EFI patients (884), DFI was observed in 35% (308). Younger age (p=0.003), lower discharge National Institutes of Health Stroke Scale (NIHSS) score (p<0.0001), and absence of any hemorrhage (p=0.021) were independent predictors of DFI. After age 60, the probability of DFI declines significantly with 5 year age increments (approximately 7% decline for every 5 years; p(DFI)= 1.3559-0.0699, p for slope=0.001). The DEFIANT score is available online (https://bit.ly/3KZRVq5). CONCLUSION: Approximately 45% of patients experience EFI. About one-third of non-early improvers experience DFI. Younger age, lower discharge NIHSS score, and absence of any hemorrhage were independent predictors of DFI among non-early improvers.

First pass effect in patients with large vessel occlusion strokes undergoing neurothrombectomy: insights from the Trevo Retriever Registry.

BACKGROUND: First pass effect (FPE), defined as near-total/total reperfusion of the territory (modified Thrombolysis in Cerebral Infarction (mTICI) 2c/3) of the occluded artery after a single thrombectomy attempt (single pass), has been associated with superior safety and efficacy outcomes than in patients not experiencing FPE. OBJECTIVE: To characterize the clinical features, incidence, and predictors of FPE in the anterior and posterior circulation among patients enrolled in the Trevo Registry. METHODS: Data were analyzed from the Trevo Retriever Registry. Univariate and multivariable analyses were used to assess the relationship of patient (demographics, clinical, occlusion location, collateral grade, Alberta Stroke Program Early CT Score (ASPECTS)) and device/technique characteristics with FPE (mTICI 2c/3 after single pass). RESULTS: FPE was achieved in 27.8% (378/1358) of patients undergoing anterior large vessel occlusion (LVO) thrombectomy. Multivariable regression analysis identified American Society of Interventional and Therapeutic Neuroradiology (ASITN) levels 2-4, higher ASPECTS, and presence of atrial fibrillation as independent predictors of FPE in anterior LVO thrombectomy. Rates of modified Rankin Scale (mRS) score 0-2 at 90 days were higher (63.9% vs 53.5%, p<0.0006), and 90-day mortality (11.4% vs 12.8%, p=0.49) was comparable in the FPE group and non-FPE group. Rate of FPE was 23.8% (19/80) among basilar artery occlusion strokes, and outcomes were similar between FPE and non-FPE groups (mRS score 0-2, 47.4% vs 52.5%, p=0.70; mortality 26.3% vs 18.0%, p=0.43). Notably, there were no difference in outcomes in FPE versus non-FPE mTICI 2c/3 patients. CONCLUSION: Twenty-eight percent of patients undergoing anterior LVO thrombectomy and 24% of patients undergoing basilar artery occlusion thrombectomy experience FPE. Independent predictors of FPE in anterior circulation LVO thrombectomy include higher ASITN levels, higher ASPECTS, and the presence of atrial fibrillation.

Endovascular therapy in the distal neurovascular territory: results of a large prospective registry.

BACKGROUND: There is a paucity of data regarding mechanical thrombectomy (MT) in distal arterial occlusions (DAO). We aim to evaluate the safety and efficacy of MT in patients with DAO and compare their outcomes with proximal arterial occlusion (PAO) strokes. METHODS: The Trevo Registry was a prospective open-label MT registry including 2008 patients from 76 sites across 12 countries. Patients were categorized into: PAO: intracranial ICA, and MCA-M1; and DAO: MCA-M2, MCA-M3, ACA, and PCA. Baseline and outcome variables were compared across the PAO vs DAO patients with pre-morbid mRS 0-2. RESULTS: Among 407 DAOs including 350 (86.0%) M2, 25 (6.1%) M3, 10 (2.5%) ACA, and 22 (5.4%) PCA occlusions, there were 376 DAO with pre-morbid mRS 0-2 which were compared with 1268 PAO patients. The median baseline NIHSS score was lower in DAO (13 [8-18] vs 16 [12-20], P<0.001). There were no differences in terms of age, sex, IV-tPA use, co-morbidities, or time to treatment across DAO vs PAO. The rates of post-procedure reperfusion, symptomatic intracranial hemorrhage (sICH), and 90-mortality were comparable between both groups. DAO showed significantly higher rates of 90-day mRS 0-2 (68.3% vs 56.5%, P<0.001). After adjustment for potential confounders, the level of arterial occlusion was not associated with the chances of excellent outcome (DAO for 90-day mRS 0-1: OR; 1.18, 95% CI [0.90 to 1.54], P=0.225), successful reperfusion or SICH. However, DAO patients were more likely to be functionally independent (mRS 0-2: OR; 1.45, 95% CI [1,09 to 1.92], P=0.01) or dead (OR; 1.54, 95% CI [1.06 to 2.27], P=0.02) at 90 days. CONCLUSION: Endovascular therapy in DAO appears to result in a comparable safety and technical success profile as in PAO. The potential benefits of DAO thrombectomy should be investigated in future randomized trials.

Risk Factors for Acute Choroidal Ischemia after Intra-arterial Melphalan for Retinoblastoma: The Role of the Catheterization Approach.

PURPOSE: To identify risk factors for acute choroidal ischemia (ACI) after intra-arterial chemotherapy (IAC) for retinoblastoma. DESIGN: Retrospective cohort study. PARTICIPANTS: Two hundred twenty patients (248 eyes) treated with IAC in Lausanne between November 2008 and September 2019 (665 procedures). All patients were evaluated on a monthly basis with fundus photography and fluorescein angiography before and after each IAC injection. METHODS: Acute choroidal ischemia, defined as any new choroidal ischemia clinically diagnosed within 35 days after an IAC injection, were noted. Eyes with choroidal complications diagnosed later than 35 days after the last IAC injection (n = 7) or those for which the status of the choroid was not assessable (n = 35) were excluded. Specific procedure parameters and treatment regimens were compared between the group of eyes with and without ACI. MAIN OUTCOME MEASURES: Procedure-related risk factors for ACI after IAC injection and visual acuity assessment in the group of eyes with ACI. RESULTS: Acute choroidal ischemia developed in 35 of 206 included eyes after a mean of 2 injections. No differences were found between the two study groups regarding age at first IAC injection, disease grouping at diagnosis, previously administered treatments, number of IAC injections, drug dose, mean injection time, injection method (pulsatile vs. continuous), or concomitant intravitreal melphalan use. Treatment regimen (melphalan vs. combined melphalan plus topotecan; P < 0.05), catheterization route (internal carotid artery vs. external carotid or posterior communicating artery; P < 0.001), and catheterization type (occlusive into the ophthalmic artery [OA] vs. nonocclusive; P < 0.001) were included in multivariate analysis, and occlusive catheterization was identified as an independent risk factor for ACI (P < 0.001). In the subgroup undergoing an occlusive procedure, placement of the catheter tip into the OA distal third versus medial and proximal thirds (P = 0.04) and a mean catheter diameter-to-OA lumen ratio of 0.6 or more (P < 0.001) were correlated significantly with ACI. Complete vision loss was noted in 27% of the eyes with ACI that were old enough for visual assessment (n = 9/33), whereas 33% maintained a useful vision ranging between 0.1 and 0.8 (n = 11/33). CONCLUSIONS: Catheterization of the OA should be attempted from an ostial position or an external carotid approach to minimize the risk of potentially vision-threatening choroidal complications.

Middle meningeal artery occlusion for intra-arterial chemotherapy of retinoblastoma.

We report the intentional occlusion of the middle meningeal artery arising from the lacrimal artery, a novel technique to improve drug delivery in a 14-month-old boy with a history of right sporadic unilateral cavitary retinoblastoma group D. The patient was referred to our institution for intra-arterial chemotherapy after two systemic chemotherapy treatments. The digital subtraction angiography showed a large middle meningeal artery arising from the right lacrimal artery and decrease choroidal enhancement thus decreased flow to the tumor. The ophthalmological examination after the first intra-arterial chemotherapy observed no tumor regression. Assuming a vascular steal, in the second intra-arterial chemotherapy session, the origin of the middle meningeal artery was occluded. Following this treatment, a significant response was observed at ophthalmological follow up. In the presented case, the efficacy of intra-arterial chemotherapy was improved after occlusion of a meningeal branch arising from the lacrimal artery, which was responsible for the vascular steal.

Inter- and intraobserver reliability for angiographic leptomeningeal collateral flow assessment by the American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology (ASITN/SIR) scale.

BACKGROUND: The adequacy of leptomeningeal collateral flow has a pivotal role in determining clinical outcome in acute ischemic stroke. The American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology (ASITN/SIR) collateral score is among the most commonly used scales for measuring this flow. It is based on the extent and rate of retrograde collateral flow to the impaired territory on angiography. OBJECTIVE: To evaluate inter- and intraobserver agreementin angiographic leptomeningeal collateral flow assessment. MATERIALS AND METHODS: Thirty pretreatment angiogram video loops (frontal and lateral view), chosen from the randomized controlled trial THRombectomie des Artères CErebrales (THRACE), were sent for grading in an electronic file. 19 readers participated, including eight who had access to a training set before the first grading. 13 readers made a double evaluation, 3 months apart. RESULTS: Overall agreement among the 19 observers was poor (κ = 0,16 ± 6,5.10 -3), and not improved with prior training (κ = 0,14 ± 0,016). Grade 4 showed the poorest interobserver agreement (κ=0.18±0.002) while grades 0 and 1 were associated with the best results (κ=0.52±0.001 and κ=0.43±0.004, respectively). Interobserver agreement increased (κ = 0,27± 0,014) when a dichotomized score, 'poor collaterals' (score of 0, 1 or 2) versus 'good collaterals' (score of 3 or 4) was used. The intraobserver agreements varied between slight (κ=0.18±0.13) and substantial (κ=0.74±0.1), and were slightly improved with the dichotomized score (from κ=0.19±0.2 to κ=0.79±0.11). CONCLUSION: Inter- and intraobserver agreement of collateral circulation grading using the ASITN/SIR score was poor, raising concerns about comparisons among publications. A simplified dichotomized judgment may be a more reproducible assessment when images are rated by the same observer(s) in randomized trials.

Evaluating the effectiveness and safety of the carotid Casper-RX stent for tandem lesions in acute ischemic stroke.

INTRODUCTION: A new generation of carotid artery stents that use a dual micromesh layer to reduce embolic events during carotid artery stenting has recently been introduced. We aimed to analyze the effectiveness and safety of the new Casper-RX stent in patients experiencing acute ischemic stroke with large vessel intracranial occlusion associated with a tandem lesion (another carotid occlusion or severe stenosis). METHODS: We retrospectively analyzed all consecutive patients treated with carotid Casper-RX stents from our stroke registry. We analyzed clinical, angiographic, and neuroimaging data. Endpoints included acute intra-stent thrombus formation, stent occlusion prior to hospital discharge, 3 month modified Rankin Scale score (mRS), and symptomatic intracranial hemorrhage. RESULTS: 21 patients were included: 10 patients had tandem carotid occlusions and 11 patients had severe carotid stenosis, 8 of whom had a hemodynamically significant stenosis. We observed acute in-stent thrombus formation in 11 patients. No stent occlusion occurred prior to hospital discharge. We report no stroke recurrence at 3 months but symptomatic intracranial hemorrhage in two patients. mRS score at 3 months was 0-2 (favorable) for 15 patients (71%), 3-5 for 3 patients, and 6 for 3 patients. CONCLUSIONS: In the present series, we frequently observed clot formation during the procedure with Casper-RX stents, which required periprocedural intravenous infusion of anticoagulant and antiplatelet treatment. This motivated us, in the absence of a prospective randomized controlled study demonstrating the non-inferiority of micromesh dual layer stents compared with the single layer design, to discontinue using this stent type in acute stroke requiring carotid angioplasty.

Mechanical thrombectomy with the ERIC retrieval device: initial experience.

OBJECTIVE: To report our experience with the Embolus Retriever with Interlinked Cage (ERIC) stentriever for use in mechanical endovascular thrombectomy (MET). METHODS: Thirty-four consecutive patients with acute stroke (21 men and 13 women; median age 66 years) determined appropriate for MET were treated with ERIC and prospectively included over a 6-month period at three different centers. The ERIC device differs from typical stentrievers in that it is designed with a series of interlinked adjustable nitinol cages that allow for fast thrombus capture, integration, and withdrawal. The evaluated endpoints were successful revascularization (Thrombolysis in Cerebral Infarction (TICI) 2b-3) and good clinical outcomes at 3 months (modified Rankin Scale (mRS) 0-2). RESULTS: Locations of the occlusions included the middle cerebral artery (13 patients), terminal carotid artery (11 patients), basilar artery (1 patient), and tandem occlusions (9 patients). IV thrombolysis was performed in 20/34 (58.8%) patients. Median times from symptom onset to recanalization and from puncture to recanalization were 325.5 min (180-557) and 78.5 min (14-183), respectively. Used as the first-line device, ERIC achieved a successful recanalization in 20/24 (83.3%) patients. Successful recanalization was associated with lower National Institutes of Health Stroke Scale scores at 24 h (8±6.5 vs 21.5±2.1; p=0.008) and lower mRS at 3 months (2.7±2.1 vs 5.3±1.1; p=0.04). Three procedural complications and four asymptomatic hemorrhages were recorded. Good clinical outcomes at 3 months were seen in 15/31 (48.4%) patients. CONCLUSIONS: The ERIC device is an innovative stentriever allowing fast, effective, and safe MET.

The Capillary Index Score before thrombectomy: an angiographic correlate of favorable outcome.

BACKGROUND AND PURPOSE: The angiography based Capillary Index Score (CIS) has recently emerged as a potential surrogate marker of cerebral perfusion before intra-arterial thrombolysis. We assessed the prevalence of a favorable CIS (f-CIS) and its relationship with clinical outcome in patients treated by mechanical thrombectomy (MT). METHODS: Data from consecutive patients treated by MT from acute middle cerebral artery (MCA) occlusion were retrospectively analyzed. CIS was calculated from a pre-intervention cerebral angiogram. Association with favorable clinical outcome (modified Rankin Scale score ≤2) at 3 months was assessed in multivariate analysis. RESULTS: 146 patients were included in the study. f-CIS was observed in 106/146 (72%) patients with an acceptable inter-rater agreement (κ=0.73, p<0.001). It was associated with a lower pretreatment National Institutes of Health Stroke Scale (NIHSS) score (p=0.014), an isolated M1/M2 occlusion without internal carotid occlusion (p=0.042), and an Alberta Stroke Program Early CT Score (ASPECTS) >4 (p=0.004). In binary regression, a favorable outcome was independently associated with f-CIS (OR (-95% CI, +95% CI)=3.8 (1.3 to 10.9), p=0.013), as well as NIHSS (p=0.007), ASPECTS (p=0.005), isolated M1/M2 occlusion (p=0.013), and age (p=0.032). The positive predictive value of f-CIS for a favorable outcome was 67%. CONCLUSIONS: f-CIS was strongly associated with a favorable outcome after MT of acute MCA occlusion. As an easy surrogate marker of cerebral perfusion, it may be a useful-albeit not sufficient-diagnostic test to select patients just before an MT or to manage them after recanalization.

Endovascular treatment of cribriform plate dural arteriovenous fistulas: technical difficulties and complications avoidance.

OBJECTIVE: Cribriform plate dural arteriovenous fistula (dAVF) is a rare pathology, for which the treatment of choice used to be neurosurgery. Technological advances in micro-catheters and embolic agents permitted new endovascular alternatives. METHODS: We included all patients treated endovascularly for a cribriform plate dAVF between 2008 and 2013. We retrospectively analysed data focusing on the type of treatment chosen. RESULTS: Ten patients were treated by endovascular approach, with a need for an additional surgical exclusion of the fistula in two cases. Thirteen embolisation sessions were done. Embolisation of the fistula through an ethmoidal artery was the technique of choice; the catheterism of the ophthalmic artery was impossible in two cases and the embolic agent did not penetrate in four cases. The embolisation through the middle meningeal artery was successful in one case but the tortuosity of this artery prevented good penetration of the embolic agent. Venous approach was successful in all cases but was limited to fistulas with superficial venous drainage. CONCLUSIONS: Endovascular treatment of cribriform plate dAVF is safe and effective. The embolisation through ethmoidal artery is the method of choice. Branches of the middle meningeal artery are tortuous and prevent the penetration of embolic agent. Venous approach is effective but is limited to cases of failure of the arterial approach.

Multimodal angiographic assessment of cerebral arteriovenous malformations: a pilot study.

PURPOSE: We describe our protocol of three-dimensional (3D) Roadmap intracranial navigation and image fusion for analysis of the angioarchitecture and endovascular treatment of brain arteriovenous malformations (AVMs). METHODS: We performed superselective catheterization of brain AVMs feeders under 3D-Roadmap navigation. Angiograms of each catheterized artery on two registered orthogonal views were transferred to the imaging workstations, and dedicated postprocessing imaging software allowed automated multiple overlays of the arterial supply of the AVM superselective acquisitions on the global angiogram in angiographic or 3D views and on coregistered MRI datasets. RESULTS: 11 untreated brain AVMs (4 with hemorrhagic presentation) were explored. The superselective acquisitions were performed under 3D-Roadmap navigation in 74 arteries, for a total of 79 targeted arteries. Imaging analysis was available at table side or postoperatively for discussion of the therapeutic strategy. No complications occurred during superselective catheterization. The accuracy of the coregistration of angiogram and MRI was submillimetric after automated mutual information coregistration, with manual re-registration by the physicians. CONCLUSIONS: Superselective angiograms acquired under 3D-Roadmap navigation can be postprocessed with multiple overlays. The fluoroscopic navigation under 3D-Roadmapping and the coregistration of 3D rotational angiography, selective angiography, and 3D MR datasets appears reliable with millimeter accuracy, and could be implemented in the critical brain AVM embolization setting to allow refined analysis of AVM angioarchitecture.

Angiographic factors influencing the success of endovascular treatment of arteriovenous malformations involving the corpus callosum.

OBJECTIVE: Arteriovenous malformations (AVMs) of the corpus callosum are rare lesions, accounting for 9-11% of brain AVMs. Microsurgical resection of such lesions is difficult because of their deep location, and also because of possible neuropsychological disasters resulting from extended callosal resection. The introduction of endovascular and radiation therapies has fundamentally changed the outcome of these lesions. METHODS: We prospectively collected clinical and angiographic data on cerebral AVMs from 1995. We reviewed data from patients treated for an AVM of the corpus callosum and identified the factors influencing the endovascular approach of such lesions. RESULTS: 38 patients (mean age 31 years) were consecutively treated by endovascular techniques. 78.9% (30 cases) of patients presented with intracranial hemorrhage. 15 AVMs (39.5%) were anterior, 18 (47.4%) were posterior, and five (13.1%) were holocallosal. The Spetzler-Martin grade was I in two cases (5.2%), II in 20 cases (52.6%), III in nine cases (23.7%), IV in six cases (15.8%), and V in one case (2.6%). The nidus was compact in 19 cases (50%), diffuse in 13 (34.2%), and multifocal in six (15.8%). Both anterior and posterior circulation branches fed 14 nidi (36.8%). Venous drainage was superficial in three cases (7.9%), deep in 28 (73.7%), and both in seven cases (18.4%). 104 sessions were performed, with a procedural complication rate of 6.7%. Mean follow-up was 43.6 months, with the last modified Rankin Scale score <3 in 33 cases (86.8%). 22 patients (57.9%) were totally cured. Univariate analysis of factors influencing the success of endovascular treatment showed that Spetzler-Martin grade ≥3 (p=0.046), nidus >30 mm (p=0.02), extension in an eloquent area (p=0.03), and holocallosal type (p0.005) significantly diminished the chances of cure of the AVM. CONCLUSIONS: AVMs of the corpus callosum seems to be difficult to treat with endovascular therapy alone. The goal of embolization should be prevention of (re) bleeding and a decrease in nidus size. Our experience regarding this sub-pathology suggests that a combination of endovascular therapy and radiotherapy may be the best option.

Predictive value of flat-panel CT for haemorrhagic transformations in patients with acute stroke treated with thrombectomy.

INTRODUCTION: Haemorrhagic transformations are pejorative for patients with acute ischaemic stroke (AIS). We estimated flat-panel CT performances to detect brain parenchymal hyperdense lesions immediately after mechanical thrombectomy directly on the angiography table in patients with AIS, and its ability to predict haemorrhagic transformation. We also evaluated an easy-reading protocol for post-procedure flat-panel CT evaluation by clinicians to enable them to determine the potential risk of haemorrhage. METHODS: Two neuroradiologists retrospectively reviewed post-procedural flat-panel CT and 24 h follow-up imaging. We evaluated hyperdense lesions on flat-panel CT to predict the occurrence of haemorrhagic transformation within 24 h detected with conventional imaging. RESULTS: Of 63 patients, 60.3% presented post-procedural parenchymal hyperdensity and 54.0% had haemorrhagic transformation. Significantly more patients with hyperdense lesions on post-thrombectomy flat-panel CT presented haemorrhagic transformation (84.2% vs 8.0%; p<0.0001). No significant haemorrhagic transformations were detected for patients without parenchymal hyperdensity. Sensitivity and specificity of hyperdense lesions on flat-panel CT for the prediction of haemorrhagic transformation were 94.1% (80.3-99.3%) and 79.3% (60.3-92.0%), respectively. The positive and negative predictive values for the occurrence of haemorrhage were 84.2% (68.8-94.0%) and 92.0% (74.0-99.0%), respectively. For significant parenchymal haemorrhage type 2, sensitivity and negative predictive values were 100%. We observed good homogeneity between the different readers. Hyperdensity on post-procedural flat-panel CT was associated with a tendency for higher risk of death and lower risk of good clinical outcome. CONCLUSIONS: Flat-panel CT appears to be a good tool to detect brain parenchymal hyperdensities after mechanical thrombectomy in patients with AIS and to predict haemorrhagic transformation.

Access to the ophthalmic artery by retrograde approach through the posterior communicating artery for intra-arterial chemotherapy of retinoblastoma.

Intra-arterial infusion of chemotherapy into the ophthalmic artery for treatment of retinoblastoma has been realized after catheterization of the internal carotid and temporary balloon occlusion beyond the orifice of the ophthalmic artery, or more recently after superselective canulation of the ophthalmic artery by a microcatheter. The superselective catheterization of the ophthalmic artery could be cumbersome because of the implantation of the ostium on the carotid siphon or because of the tortuosity of the carotid siphon. We report our experience of using a retrograde approach through the posterior communicating artery that allows a more direct angle of access to the origin of the ophthalmic artery.