Intracranial dural arteriovenous fistulas: association with cerebral venous thrombosis, baseline aggressiveness, and clinical outcomes. A retrospective multicenter study on 263 consecutive patients and literature review

OBJECTIVE

The pathogenesis of intracranial dural arteriovenous fistulas (icDAVFs) is controversial. Cerebral vein thrombosis (CVT) and venous hypertension are recognized predisposing factors. This study aimed to evaluate the incidence of association between icDAVF and CVT and describe baseline aggressiveness and clinical outcomes for icDAVFs associated with CVT. The authors also performed a literature review of studies reporting icDAVF associated with CVT.

METHODS

Two hundred sixty-three consecutive patients in two university hospitals with confirmed icDAVFs were included. A double-blind imaging review was performed to determine the presence or absence of CVT close or distant to the icDAVF. Location, type (using the Cognard classification), aggressiveness of the icDAVF, clinical presentation, treatment modality, and clinical and/or angiographic outcomes at 6 months were also collected. All prior brain imaging was analyzed to determine the natural history of onset of the icDAVF.

RESULTS

Among the 263 included patients, 75 (28.5%) presented with a CVT concomitant to their icDAVF. For 18 (78.3%) of 23 patients with previous brain imaging available, CVT preceding the icDAVF was proven (6.8% of the overall population). Former/active smoking (OR 2.0, 95% CI 1.079-3.682, p = 0.022) and prothrombogenic status (active inflammation or cancer/coagulation trouble) were risk factors for CVT associated with icDAVF (OR 3.135, 95% CI 1.391-7.108, p = 0.003). One hundred eighty-seven patients (71.1%) had a baseline aggressive icDAVF, not linked to the presence of a CVT (p = 0.546). Of the overall population, 11 patients (4.2%) presented with spontaneous occlusion of their icDAVF at follow-up. Seven patients (2.7%) died during the follow-up period. Intracranial DAVF + CVT was not associated with a worse prognosis (modified Rankin Scale score at 3-6 months: 0 [interquartile range {IQR} 0-1] for icDAVF + CVT vs 0 [IQR 0-0] for icDAVF alone; p = 0.055).

CONCLUSIONS

This was one of the largest studies focused on the incidence of CVT associated with icDAVF. For 6.8% of the patients, a natural history of CVT leading to icDAVF was proven, corresponding to 78.3% of patients with previous imaging available. This work offers further insights into icDAVF pathophysiology, aiding in identifying high-risk CVT patients for long-term follow-up imaging. Annual imaging follow-up using noninvasive vascular imaging (CT or MR angiography) for a minimum of 3 years after the diagnosis of CVT should be considered in high-risk patients, i.e., smokers and those with prothrombogenic status.

Evaluation of mechanical thrombectomy in acute ischemic stroke related to a distal arterial occlusion: A randomized controlled trial

RATIONALE

Mechanical thrombectomy (MT) associated with the best medical treatment (BMT) has recently shown efficacy for the management of acute ischemic stroke (AIS) secondary to a large vessel occlusion. However, evidence is lacking regarding the benefit of MT for more distal occlusions.

AIM

To evaluate the efficacy in terms of good clinical outcome at 3 months of MT associated with the BMT over the BMT alone in AIS related to a distal occlusion.

METHODS

The DISCOUNT trial is a multicenter open-label randomized controlled trial involving French University hospitals. Adult patients (⩾18 years) with an AIS involving the anterior or posterior circulation secondary to a distal vessel occlusion within 6 h of symptom onset or within 24 h if no hyperintense signal on fluid attenuation inversion recovery acquisition will be randomized 1:1 to receive either MT associated with the BMT (experimental group) or BMT alone (control group). The number of patients to be included is 488.

STUDY OUTCOMES

The primary outcome is the rate of good clinical outcome at 3 months defined as a modified Rankin scale (mRS) ⩽2 and evaluated by an independent assessor blinded to the intervention arm. Secondary outcomes include recanalization of the occluded vessel within 48 h, angiographic reperfusion in the experimental group, 3-month excellent clinical outcome (mRS ⩽ 1), all adverse events, and death. A cost utility analysis will estimate the incremental cost per quality-adjusted life year (QALY) gained.

DISCUSSION

If positive, this study will open new insights in the management of AISs.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT05030142 registered on 1 September 2021.

The Management of Persistent Distal Occlusions after Mechanical Thrombectomy and Thrombolysis: An Inter- and Intrarater Agreement Study

BACKGROUND AND PURPOSE

The best management of patients with persistent distal occlusion after mechanical thrombectomy with or without IV thrombolysis remains unknown. We sought to evaluate the variability and agreement in decision-making for persistent distal occlusions.

MATERIALS AND METHODS

A portfolio of 60 cases was sent to clinicians with varying backgrounds and experience. Responders were asked whether they considered conservative management or rescue therapy (stent retriever, aspiration, or intra-arterial thrombolytics) a treatment option as well as their willingness to enroll patients in a randomized trial. Agreement was assessed using κ statistics.

RESULTS

The electronic survey was answered by 31 physicians (8 vascular neurologists and 23 interventional neuroradiologists). Decisions for rescue therapies were more frequent (n = 1116/1860, 60%) than for conservative management (n = 744/1860, 40%; P < .001). Interrater agreement regarding the final management decision was "slight" (κ = 0.12; 95% CI, 0.09-0.14) and did not improve when subgroups of clinicians were studied according to background, experience, and specialty or when cases were grouped according to the level of occlusion. On delayed re-questioning, 23 of 29 respondents (79.3%) disagreed with themselves on at least 20% of cases. Respondents were willing to offer trial participation in 1295 of 1860 (69.6%) cases.

CONCLUSIONS

Individuals did not agree regarding the best management of patients with persistent distal occlusion after mechanical thrombectomy and IV thrombolysis. There is sufficient uncertainty to justify a dedicated randomized trial.

Safety and effectiveness of the LVIS and LVIS Jr devices for the treatment of intracranial aneurysms: Final results of the LEPI multicenter cohort study

BACKGROUND

The Low profile visualized intraluminal support (LVIS)/LVIS Jr is a self-expanding braiding stent for the treatment of intracranial aneurysm. This study is to determine the safety and effectiveness of the LVIS/LVIS Jr for the treatment of intracranial aneurysms in a real-world setting.

METHODS

This prospective, observational, multicenter study enrolled patients with unruptured, ruptured and recanalized intracranial aneurysms treated with the LVIS stents, between February 2018 to December 2019. Primary endpoint was the cumulative morbidity and mortality rate (CMMR) assessed at 12 months follow-up (FU).

RESULTS

A total of 130 patients were included (62.3 % women, mean age 55.9 ± 11.4) on an intention-to-treat basis. Four patients (3.1 %) had 2 target aneurysms; 134 total aneurysms were treated. The aneurysms were mainly located on the middle cerebral artery (41/134; 30.6 %) and the anterior communicating artery (31/134; 23.1 %). The CMMR at 1 year linked to the procedure and/or device was 4.6 % (6/130). The overall mortality was 1.5 % (2/130), none of these deaths adjudged as being linked to the procedure and/or device. All aneurysms (134/134, 100 %) were successfully treated with LVIS stent and/or other devices. At a mean FU of 16.8 months post-procedure, complete/nearly complete occlusion was achieved in 112 aneurysms (92.6 %), and only 3 patients (2.5 %) required aneurysm retreatment.

CONCLUSION

This study provides evidence that the LVIS/LVIS Jr devices are safe and effective in the treatment of complex intracranial aneurysms, with very high rates of adequate occlusion at FU. These angiographic results are stable over time with an acceptable complication rate.

TRIAL REGISTRATION

ClinicalTrial.gov under NCT03553771.

Temporal trends in results of endovascular treatment of anterior intracranial large cerebral vessel occlusion: A 7-year study

BACKGROUND

Technical improvements in devices, changes in angiographic grading scales and various confounding factors have made difficult the detection of the temporal evolution of angiographic and clinical results after endovascular treatment (EVT) for acute ischemic Stroke (AIS). We analyzed this evolution in time using the Endovascular Treatment in Ischemic Stroke (ETIS) registry.

MATERIALS AND METHODS

We analyzed the efficacy outcomes of EVT performed from January 2015 to January 2022, and modelized the temporal trends using mixed logistic regression models, further adjusted for age, intravenous thrombolysis prior to EVT, general anesthesia, occlusion site, balloon catheter use and the type of first-line EVT strategy. We assessed heterogeneity in temporal trends according to occlusion site, balloon catheter use, cardio embolic etiology, age (<80 years vs ⩾80 years) and first-line EVT strategy.

RESULTS

Among 6104 patients treated from 2015 to 2021, the rates of successful reperfusion (71.1%-89.6%) and of complete first pass effect (FPE) (4.6%-28.9%) increase, whereas the rates of patients with >3 EVT device passes (43.1%-17.5%) and favorable outcome (35.8%-28.9%) decrease significantly over time. A significant heterogeneity in temporal trends in successful reperfusion according to the first-line EVT strategy was found (p-het = 0.018). The temporal trend of increasing successful reperfusion rate was only significant in patients treated with contact aspiration in first-line (adjusted overall effect p = 0.010).

CONCLUSION

In this 7-year-old large registry of ischemic stroke cases treated with EVT, we observed a significant increase with time in the rate of recanalization whereas there was a tendency toward a decrease in the rate of favorable outcome over the same period.

Comparison of arterial wall integration of different flow diverters in rabbits: The CICAFLOW study

BACKGROUND AND PURPOSE

New coated flow diverters (FDs) claim antithrombotic properties and increased arterial wall integration. The aim of this study is to compare in vivo endothelial coverage of coated and uncoated FD in the context of different antiplatelet regimens.

METHODS

Different FDs (Silk Vista - SV, Pipeline with Shield technology - PED shield and Surpass Evolve - SE) were implanted in the aorta of rabbits, all 3 in each animal with 3 different antiplatelet regimens: no antiplatelet therapy, aspirin alone, or aspirin and ticagrelor. Four weeks after FD implantation, angiography, flat-panel CT, and optical coherence tomography (OCT) were performed before harvesting the aorta. Extensive histopathology analyses were performed including environmental scanning electron microscopy (ESEM), multiphoton microscopy (MPM) and histological staining with qualitative and/or quantitative assessment of device coverage.

RESULTS

All 23 FDs that were implanted remained patent without hyperplasia. Qualitative stent coverage assessment revealed that there were no statistically significant differences between the FD groups (p = 0.19, p = 0.45, p = 0.40, and p = 0.84 for OCT, ESEM, MPM and histology, respectively). Quantitative neointimal measurement of histological sections also showed similar results in all 3 FD groups (p = 0.70). However, there were significant differences between the 3 groups of antiplatelet regimens (p = 0.07) with a higher rate in the no antiplatelet group (p = 0.05 versus aspirin alone and p = 0.03 versus aspirin and ticagrelor).

CONCLUSION

Our study provides evidence that FD integration into the arterial wall is similar with coated (PED shield) and uncoated devices (SV, SE), regardless of the antiplatelet regimen. FD integration with specific surface coverage should be promoted.

TRIAL REGISTRATION

APAFIS #2022011215518538.

Endovascular treatment of brain arteriovenous malformations: clinical outcomes of patients included in the registry of a pragmatic randomized trial

OBJECTIVE

The role of endovascular treatment in the management of patients with brain arteriovenous malformations (AVMs) remains uncertain. AVM embolization can be offered as stand-alone curative therapy or prior to surgery or stereotactic radiosurgery (SRS) (pre-embolization). The Treatment of Brain AVMs Study (TOBAS) is an all-inclusive pragmatic study that comprises two randomized trials and multiple registries.

METHODS

Results from the TOBAS curative and pre-embolization registries are reported. The primary outcome for this report is death or dependency (modified Rankin Scale [mRS] score > 2) at last follow-up. Secondary outcomes include angiographic results, perioperative serious adverse events (SAEs), and permanent treatment-related complications leading to an mRS score > 2.

RESULTS

From June 2014 to May 2021, 1010 patients were recruited in TOBAS. Embolization was chosen as the primary curative treatment for 116 patients and pre-embolization prior to surgery or SRS for 92 patients. Clinical and angiographic outcomes were available in 106 (91%) of 116 and 77 (84%) of 92 patients, respectively. In the curative embolization registry, 70% of AVMs were ruptured, and 62% were low-grade AVMs (Spetzler-Martin grade I or II), while the pre-embolization registry had 70% ruptured AVMs and 58% low-grade AVMs. The primary outcome of death or disability (mRS score > 2) occurred in 15 (14%, 95% CI 8%–22%) of the 106 patients in the curative embolization registry (4 [12%, 95% CI 5%–28%] of 32 unruptured AVMs and 11 [15%, 95% CI 8%–25%] of 74 ruptured AVMs) and 9 (12%, 95% CI 6%–21%) of the 77 patients in the pre-embolization registry (4 [17%, 95% CI 7%–37%] of 23 unruptured AVMs and 5 [9%, 95% CI 4%–20%] of 54 ruptured AVMs) at 2 years. Embolization alone was confirmed to occlude the AVM in 32 (30%, 95% CI 21%–40%) of the 106 curative attempts and in 9 (12%, 95% CI 6%–21%) of 77 patients in the pre-embolization registry. SAEs occurred in 28 of the 106 attempted curative patients (26%, 95% CI 18%–35%, including 21 new symptomatic hemorrhages [20%, 95% CI 13%–29%]). Five of the new hemorrhages were in previously unruptured AVMs (n = 32; 16%, 95% CI 5%–33%). Of the 77 pre-embolization patients, 18 had SAEs (23%, 95% CI 15%–34%), including 12 new symptomatic hemorrhages [16%, 95% CI 9%–26%]). Three of the hemorrhages were in previously unruptured AVMs (3/23; 13%, 95% CI 3%–34%).

CONCLUSIONS

Embolization as a curative treatment for brain AVMs was often incomplete. Hemorrhagic complications were frequent, even when the specified intent was pre-embolization before surgery or SRS. Because the role of endovascular treatment remains uncertain, it should preferably, when possible, be offered in the context of a randomized trial.

Flow Diversion for ICA Aneurysms with Compressive Neuro-Ophthalmologic Symptoms: Predictors of Morbidity, Mortality, and Incomplete Aneurysm Occlusion

BACKGROUND AND PURPOSE

Flow diversion is an effective treatment for aneurysms of the ICA with compression-related neuro-ophthalmologic symptoms, especially when treatment is initiated early after symptom onset and aneurysm occlusion is complete. However, non-negligible complication rates have been reported. Our aim was to identify risk factors for morbidity/mortality and incomplete aneurysm occlusion.

MATERIALS AND METHODS

We performed a secondary analysis of a previous publication, which included all patients treated with flow diversion for an unruptured aneurysm of the ICA with compression-related symptoms.

RESULTS

Fifty-four patients with 54 aneurysms (48 women, 88.9%; mean age, 59.2 [SD, 15.9] years; range, 21-86 years) treated with flow diversion were included. We observed morbidity and mortality rates of 7.4% and 3.7%. Increasing age (OR per decade, 3.2; 95% CI, 1.23-8.49; P = .02) and dual-antiplatelet therapy with ticagrelor (OR, 13.9; 95% CI, 1.16-165.97; P = .04) were significantly associated with morbidity/mortality. After a median follow-up of 13.3 [SD, 10.5] months, the rates of complete aneurysm occlusion, neck remnant, and aneurysm remnant were 74%, 14%, and 12%. Incomplete occlusion at follow-up was less frequently observed in aneurysms treated with additional coil embolization (OR, 0.1; 95% CI, 0.01-0.86; P = .04).

CONCLUSIONS

Although a promising treatment for compressive ICA aneurysms, flow diversion carries a relevant risk for complications and incomplete aneurysm occlusion. Our results may help identify patients in which flow diversion may not be the ideal treatment method. Additional coil embolization increased the likelihood of complete aneurysm occlusion at follow-up.

Parent Artery Straightening after Flow-Diverter Stenting Improves the Odds of Aneurysm Occlusion

BACKGROUND AND PURPOSE

Intracranial stents for the treatment of aneurysms can be responsible for parent artery straightening, a phenomenon with potential consequences for aneurysmal occlusion. We aimed to evaluate parent artery straightening following flow-diverter stent placement in patients with intracranial aneurysms and explored the association between parent artery straightening and subsequent aneurysm occlusion.

MATERIALS AND METHODS

All patients treated with flow-diverter stents for anterior circulation aneurysms located downstream from the carotid siphon between January 2009 and January 2018 were screened for inclusion. Parent artery straightening was defined as the difference (α-β) in the parent artery angle at the neck level before (α angle) and after flow-diverter stent deployment (β angle). We analyzed the procedural and imaging factors associated with parent artery straightening and the associations between parent artery straightening and aneurysmal occlusion.

RESULTS

Ninety-five patients met the inclusion criteria (n = 64/95 women, 67.4%; mean age, 54.1 [SD, 11.2]  years) with 97 flow-diverter stents deployed for 99 aneurysms. Aneurysms were predominantly located at the MCA bifurcation (n = 44/95, 44.4%). Parent artery straightening was found to be more pronounced in patients treated with cobalt chromium stents than with nitinol stents (P = .02). In multivariate analysis, parent artery straightening (P = .04) was independently associated with aneurysm occlusion after flow-diverter stent deployment.

CONCLUSIONS

The use of flow-diverter stents for distal aneurysms induces a measurable parent artery straightening, which is associated with higher occlusion rates. Parent artery straightening, in our sample, appeared to be more prominent with cobalt chromium stents than with nitinol stents. This work highlights the necessary trade-off between navigability and parent artery straightening and may help tailor the selection of flow-diverter stents to aneurysms and parent artery characteristics.

Relevance of Brain Regions' Eloquence Assessment in Patients With a Large Ischemic Core Treated With Mechanical Thrombectomy

OBJECTIVE

Individualized patient selection for mechanical thrombectomy (MT) in patients with acute ischemic stroke (AIS) and large ischemic core (LIC) at baseline is an unmet need. We tested the hypothesis that assessing the functional relevance of both infarcted and hypoperfused brain tissue would improve the selection framework of patients with LIC for MT.

METHODS

We performed a multicenter, retrospective study of adults with LIC (ischemic core volume >70 mL on MRI diffusion-weighted imaging) with MRI perfusion treated with MT or best medical management (BMM). Primary outcome was 3-month modified Rankin Scale (mRS), favorable if 0-3. Global and regional eloquence-based core perfusion mismatch ratios were derived. The predictive accuracy for clinical outcome of eloquent regions involvement was compared in multivariable and bootstrap random forest models.

RESULTS

A total of 138 patients with baseline LIC were included (MT n = 96 or BMM n = 42; mean age ± SD, 72.4 ± 14.4 years; 34.1% female; mRS 0-3: 45.1%). Mean core and critically hypoperfused volume were 100.4 mL ± 36.3 mL and 157.6 ± 56.2 mL, respectively, and did not differ between groups. Models considering the functional relevance of the infarct location showed a better accuracy for the prediction of mRS 0-3 with a c statistic of 0.76 and 0.83 for logistic regression model and bootstrap random forest testing sets, respectively. In these models, the interaction between treatment effect of MT and the mismatch was significant (p = 0.04). In comparison, in the logistic regression model disregarding functional eloquence, the c statistic was 0.67 and the interaction between MT and the mismatch was insignificant.

CONCLUSIONS

Considering functional eloquence of hypoperfused tissue in patients with a large infarct core at baseline allows for a more precise estimation of treatment expected benefit.

CLASSIFICATION OF EVIDENCE

This study provides Class II evidence that, in patients with AIS and LIC, considering the functional eloquence of the infarct location improves prediction of disability status at 3 months.

Safety of Oral P2Y12 Inhibitors in Interventional Neuroradiology: Current Status and Perspectives

In the field of interventional neuroradiology, antiplatelet agents are commonly used to prepare patients before the implantation of permanent endovascular materials. Among the available drugs, clopidogrel is the most frequently used one, but resistance phenomena are considered to be relatively common. Prasugrel and ticagrelor were recently added to the pharmacologic arsenal, but the safety of these agents in patients undergoing neurointerventional procedures is still a subject of discussion. The cumulative experience with both drugs is less extensive than that with clopidogrel, and the experience with patients in the neurology field is less extensive than in the cardiology domain. In the present article, we provide a narrative review of studies that investigated safety issues of oral P2Y12 inhibitors in interventional neuroradiology and discuss potential routes for future research.

EASY score (Eloquent, Age and baseline SYmptoms score) for outcome prediction in patients with acute ischemic stroke

OBJECTIVE

A pragmatic tool for the early and reliable prediction of recovery in patients with acute ischemic stroke is needed. We aimed to test the addition of brain eloquent areas involvement in variables predicting poor outcome, using a simple scoring system.

METHODS

Retrospective study of patients with anterior circulation acute ischemic stroke treated with best medical treatment and/or endovascular reperfusion. Primary outcome measure was 3-months poor outcome (mRs 3-6). We developed a prognostic model based on clinical data and a quantitative scoring system of the main eloquent brain areas involved on early follow-up CT, and analyzed its accuracy to predict poor outcome comparatively to three other prognostic models. The final model was used to develop a score for outcome prediction based on the multivariable analysis.

RESULTS

A total of 197 patients were included (poor outcome = 62; mean age 67 ± 15.1 years; 44% females). Independent predictors of poor outcome were increasing age (p < 0.001), baseline NIHSS (p = 0.03), and the involvement of two brain areas: posterior limb of internal capsule (p < 0.001) and postero-superior corona radiata (p < 0.001). This model showed to be the most accurate to predict poor outcome (Balance Accuracy = 77.74%; C-Statistic = 0.891). The derived risk score attributing points for each of these variables (EASY score) showed similar performances (Balance Accuracy = 82.11%; C-Statistic = 0.90).

CONCLUSION

The EASY score is an easy-to-apply and accurate tool to predict the 3-months functional outcome after ischemic stroke, relying on simple clinical features and the assessment of two key eloquent brain areas on early follow-up CT.

WEB Device Shape Changes in Elastase-Induced Aneurysms in Rabbits

BACKGROUND AND PURPOSE

While WEB devices have been shown to be safe and effective for aneurysm treatment, WEB-shape modification compression has been associated with incomplete aneurysm occlusion. We explored the relationship between occlusion rates and WEB-shape modification in different WEB device types in an experimental aneurysm model.

MATERIALS AND METHODS

Elastase-induced aneurysms were created in rabbits and treated with dual-layer (n = 12), single-layer (n = 12), or single-layer sphere (n = 12) WEB devices. Aneurysms were followed up either at 3 or 12 months. Angiographic occlusion was graded using the WEB Occlusion Scale: grade I, complete; grade II, complete but recess filling; grade III, residual neck; or grade IV, residual aneurysm. WEB-shape modification and histologic features were also analyzed.

RESULTS

Grade I or II occlusion was seen in 16 (44%) aneurysms, and grade I, II, or III ("adequate") occlusion was observed in 22 (61.1%) aneurysms at follow-up. WEB-shape modification was observed in 22 (61.1%) aneurysms. WEB-shape modification was higher in single-layer (9/12) and dual-layer (10/12) devices compared with single-layer sphere devices (3/12). Aneurysms with WEB-shape modification had a higher level of thrombus organization in the dome compared with those without WEB-shape modification (68% [15/22] versus 50% [7/14]). WEB-shape modification was not correlated with angiographic or histologic outcomes but was significantly correlated with levels of fibrosis and smooth muscle cells in the aneurysm.

CONCLUSIONS

WEB-shape modification is not associated with incomplete aneurysm occlusion of WEB devices in the rabbit model but may be related to connective tissue formation and the healing response to WEB device implantation.

Mechanical Thrombectomy for Acute Ischemic Stroke Amid the COVID-19 Outbreak: Decreased Activity, and Increased Care Delays

BACKGROUND AND PURPOSE

The efficiency of prehospital care chain response and the adequacy of hospital resources are challenged amid the coronavirus disease 2019 (COVID-19) outbreak, with suspected consequences for patients with ischemic stroke eligible for mechanical thrombectomy (MT).

METHODS

We conducted a prospective national-level data collection of patients treated with MT, ranging 45 days across epidemic containment measures instatement, and of patients treated during the same calendar period in 2019. The primary end point was the variation of patients receiving MT during the epidemic period. Secondary end points included care delays between onset, imaging, and groin puncture. To analyze the primary end point, we used a Poisson regression model. We then analyzed the correlation between the number of MTs and the number of COVID-19 cases hospitalizations, using the Pearson correlation coefficient (compared with the null value).

RESULTS

A total of 1513 patients were included at 32 centers, in all French administrative regions. There was a 21% significant decrease (0.79; [95%CI, 0.76-0.82]; P<0.001) in MT case volumes during the epidemic period, and a significant increase in delays between imaging and groin puncture, overall (mean 144.9±SD 86.8 minutes versus 126.2±70.9; P<0.001 in 2019) and in transferred patients (mean 182.6±SD 82.0 minutes versus 153.25±67; P<0.001). After the instatement of strict epidemic mitigation measures, there was a significant negative correlation between the number of hospitalizations for COVID and the number of MT cases (R² -0.51; P=0.04). Patients treated during the COVID outbreak were less likely to receive intravenous thrombolysis and to have unwitnessed strokes (both P<0.05).

CONCLUSIONS

Our study showed a significant decrease in patients treated with MTs during the first stages of the COVID epidemic in France and alarming indicators of lengthened care delays. These findings prompt immediate consideration of local and regional stroke networks preparedness in the varying contexts of COVID-19 pandemic evolution.

Mechanical thrombectomy practices in France: Exhaustive survey of centers and individual operators

BACKGROUND AND PURPOSE

Mechanical thrombectomy (MT) has dramatically changed the landscape of stroke care as well as stroke care organization. Public health institutions are faced with the challenge of swiftly providing equal access to this high technical level procedure with rapidly broadening indications, and constantly developing techniques. The aim of this study was to present a current nationwide overview of technical MT practices in France as well as local organizations.

MATERIALS AND METHODS

Thrombectomy capable French stroke centers, and physicians performing MT were invited to participate to a nationwide survey, disseminated through an existing trainee-led research network (the JENI-RC) under the aegis of the French Society of Neuroradiology. The survey was composed of 64 questions to collect both individual practices and general center-based information.

RESULTS

All French centers (100%) answered the survey, and 74% (110/148) of active interventional neuroradiologists (INR) performing MT completed individual questionnaires. The mean number of INR per center performing MT was 3.7±1.85, and 85% of the centers were organized for 24/7 continuity of care. MRI was the most commonly used imaging modality for stroke diagnosis and patients' selection, and perfusion imaging was routinely available in 85% of the centers. Half of centers performed yearly between 100 and 200 MT. Anesthesiologic, and technical considerations are also developed in the manuscript.

CONCLUSIONS

This nationwide survey highlights the impressive response to the challenge of reorganization of stroke care with regards to mechanical thrombectomy in France. Technical and management disparities remain. Most centers remain understaffed to properly function in the long term, but the inflow of INT trainees is substantial.

Posterior fossa tumors in children: Radiological tips & tricks in the age of genomic tumor classification and advance MR technology

Imaging plays a major role in the comprehensive assessment of posterior fossa tumor in children (PFTC). The objective is to propose a global method relying on the combined analysis of radiological, clinical and epidemiological criteria, (taking into account the child's age and the topography of the lesion) in order to improve our histological approach in imaging, helping the management and approach for surgeons in providing information to the patients' parents. Infratentorial tumors are the most frequent in children, representing mainly medulloblastoma, pilocytic astrocytoma and brainstem glioma. Pre-surgical identification of the tumor type and its aggressiveness could be improved by the combined analysis of key imaging features with epidemiologic data.

Are Anatomic Results Influenced by WEB Shape Modification? Analysis in a Prospective, Single-Center Series of 39 Patients with Aneurysms Treated with the WEB

BACKGROUND AND PURPOSE

Endovascular treatment with the flow-disrupter Woven EndoBridge aneurysm embolization system (WEB) is an innovative treatment for wide-neck bifurcation aneurysms. Prospective, multicenter studies have shown the high safety of this technique. Stability of aneurysm occlusion in long-term follow-up has been rarely studied. Moreover the "compression" phenomenon has been reported and seems to be associated with poor anatomic results. This prospective, single-center series analyzes the safety and efficacy of the WEB device in long-term follow-up in relation to WEB shape modification.

MATERIALS AND METHODS

All patients with aneurysms treated with the WEB were prospectively included in a data base. Demographics, aneurysm characteristics, adverse events, and anatomic results were retrospectively analyzed. Anatomic results and modification of the WEB shape on the follow-up examinations were independently evaluated by a core laboratory.

RESULTS

Thirty-nine patients were included. We observed few complications: intraoperative rupture in no patients (0.0%) and thromboembolic events in 3 patients (7.7%) with a permanent deficit in 1 (2.6%). At short-term, midterm, and long-term follow-up, adequate occlusion was obtained in 86.8%, 83.3%, and 87.5%, respectively. Retreatment rates were low (5.1%). At 6 months, WEB shape modification (compression/retraction) was observed in 31.6% of patients but was not associated with a lower rate of adequate occlusion.

CONCLUSIONS

This prospective, single-center series with WEB devices used in 39 patients during 3.5 years confirms data from previous multicenter studies. Treatment can be accomplished with good safety and efficacy, with a high rate of adequate occlusion. Anatomic results were not worse in case of WEB shape modification.