Angiographic Evolution of Brain Arteriovenous Malformation Angioarchitecture After Partial Endovascular Treatment.

BACKGROUND AND OBJECTIVES: Endovascular embolization of brain arteriovenous malformations (AVMs) is sometimes intentionally partial, in the case of staged treatment for instance. Residual AVMs may be prone to angioarchitectural modification during follow-up. The objective of this work is to evaluate the nature and extent of these modifications. METHODS: We performed a retrospective monocentric study on a cohort of adult patients treated by incomplete endovascular embolization for ruptured and unruptured AVMs with an available angiographic follow-up, without any intervening confounding event between the 2 angiographic examinations. AVM angioarchitectural modifications (arterial, nidal, and venous) were analyzed. Clinical and radiological data were tested in univariate analyses for association with the occurrence of AVM regression or progression. RESULTS: Eighty-two partial embolization sessions in 57 patients were included in the study. A 40% (33/82) rate of modification was found on follow-up, with 23/82 (28%) controls showing at least one angioarchitectural regression feature and 15/82 (18.3%) showing at least one angioarchitectural progression item. Nidal growth was the most frequent modification occurring after 12/82 (14.6%) embolizations. The only factor associated with nidal volume growth was a longer time interval between embolization and follow-up (median [IQR]: 190 [250] days vs 89.5[133] days in the subgroup without nidal growth; P = .02). Specific modifications of arterial supply, nidal anatomy, and venous drainage were identified and documented. CONCLUSION: Angioarchitectural modifications (both progression and regression) of brain AVMs are frequent findings after partial embolization. Nidal volume growth is associated with longer time intervals between embolization and follow-up.

Mechanical thrombectomy in basilar artery occlusions: impact of first-line strategy as a function of the occlusion level.

BACKGROUND: Retrospective studies suggest the superiority of first-line contact aspiration (CA) thrombectomy over stent-retriever (SR) in basilar artery occlusions (BAO). We aimed to investigate the impact of first-line mechanical thrombectomy per the occlusion level, considering differences in stroke etiology prevalence between proximal and distal BAO. METHODS: A retrospective, multicentric analysis of the Endovascular Treatment in Ischemic Stroke Registry (ETIS) included consecutive BAO patients treated from January 2016 to May 2022. Patients were categorized into SR (±aspiration) and CA alone groups. Occlusion levels were determined through digital subtraction angiography. Favorable clinical outcome was defined as 90-day modified Rankin Scale (mRS) 0-3. RESULTS: A total of 380 patients were analyzed (251 CA alone, 129 SR±aspiration). Globally, first-line SR showed lower recanalization rates (89.1% vs 94.8%, OR=0.29, 95% CI 0.16 to 0.53; p<0.001) and worse clinical outcomes (mRS 0-3: 46.0% vs 52.2%, OR=0.62, 95% CI 0.44 to 0.87; p=0.006) compared with CA. In proximal occlusions, SR was significantly associated with poorer clinical outcomes (mRS 0-3: 20.9% vs 37.1%; OR=0.40, 95% CI 0.19 to 0.83; p=0.014) despite similar recanalization rates. Conversely, in distal occlusions there was no difference in clinical outcomes although recanalization rates were higher with CA (modified Thrombolysis in Cerebral Infarction score (mTICI 2b/3): 97.7% vs 91.7%; OR=0.17, 95% CI 0.05 to 0.66; p=0.01). CONCLUSIONS: In our BAO population, CA demonstrated better angiographic outcomes in middle and distal occlusions and better clinical outcomes in proximal occlusions. This translated into better angiographic and clinical results in the global study population. Clinical results were particularly influenced by the negative impact of SR on 90-day mRS, independently of recanalization rates in proximal BAO.

Location specific rupture risk of intracranial aneurysms: case of ophthalmic aneurysms.

BACKGROUND: Aneurysm location is a key element in predicting the rupture risk of an intracranial aneurysm. A common impression suggests that pure ophthalmic aneurysms are under-represented in ruptured intracranial aneurysms (RIAs). The purpose of this study was to specifically evaluate the risk of rupture of ophthalmic aneurysms compared with other aneurysm locations. METHODS: This multicenter study compared the frequency of ophthalmic aneurysms in a prospective cohort of RIAs admitted to 13 neuroradiology centers between January 2021 and March 2021, with a retrospective cohort of patients with unruptured intracranial aneurysms (UIAs) who underwent cerebral angiography at the same neuroradiology centers during the same time period. RESULTS: 604 intracranial aneurysms were included in this study (355 UIAs and 249 RIAs; mean age 57 years (IQR 49-65); women 309/486, 64%). Mean aneurysm size was 6.0 mm (5.3 mm for UIAs, 7.0 mm for RIAs; P<0.0001). Aneurysm shape was irregular for 37% UIAs and 73% RIAs (P<0.0001). Ophthalmic aneurysms frequency was 14.9% of UIAs (second most common aneurysm location) and 1.2% of RIAs (second least common aneurysm location; OR 0.07 (95% CI 0.02 to 0.23), P<0.0001). CONCLUSIONS: Ophthalmic aneurysms seem to have a low risk of rupture compared with other intracranial aneurysm locations. This calls for a re-evaluation of the benefit-risk balance when considering preventive treatment for ophthalmic aneurysms.

Fusion imaging for pulmonary artery embolization: impact on fluoroscopy duration and contrast agent exposure.

OBJECTIVES: To assess the impact of fusion imaging guidance on fluoroscopy duration and volume of contrast agent used for pulmonary artery embolization. METHODS: Thirty-four consecutive patients who underwent pulmonary artery embolization for pulmonary arterio-venous malformation (n = 28) or hemoptysis (n = 6) were retrospectively included. In the experimental group (n = 15), patients were treated using fusion imaging with 2D/3D registration. In the control group (n = 19), no fusion imaging has been used. Fluoroscopy duration and amount of contrast used were measured and intergroup comparison was performed. RESULTS: The average volume of contrast agent used for embolization in the fusion group (118.3 ml) was significantly lower than in the control group (285.3 ml) (p < 0.002). The mean fluoroscopy duration was not significantly different between both groups (19.5 min in the fusion group vs 31.4 min in the control group (p = 0.10)). No significant difference was observed regarding the average X-ray exposure (Air Kerma) (p = 0.68 in the univariate analysis). Technical success rate was 100% for both groups. CONCLUSION: Fusion imaging significantly reduces contrast medium volumes needed to perform pulmonary artery embolization. The fluoroscopy duration and the X-ray exposure did not vary significantly. ADVANCES IN KNOWLEDGE: CTA-based fusion imaging using 2D-3D registration is a valuable tool for performing pulmonary artery embolization, helpful for planning and guiding catheterization.Compared to the traditional imaging guidance, fusion imaging reduces the volume of contrast agent used.

CT annulus sizing prior to transcatheter aortic valve replacement (TAVR): evaluation of free-breathing versus breath-holding acquisition.

OBJECTIVES: To assess feasibility and accuracy of aortic annulus measurements using cardiac computed tomography angiography (CTA) performed during free-breathing prior to transcatheter aortic valve replacement (TAVR). MATERIALS AND METHODS: Sixty consecutive TAVR candidates underwent free-breathing wide-detector cardiac CTA, followed by a percutaneous valve replacement. For each, a theoretical valve size was suggested through CT measurements of the annulus, then compared to the size of the actual implanted transcatheter heart valve (THV). The procedural success and the 30-day outcomes were collected. Image quality of the annulus was also studied according to subjective and objective criteria. Data of a control group of 60 patients previously evaluated on breath-holding were also evaluated. RESULTS: A total of 120 patients (mean age, 83 years ± 7, 60 men) were evaluated. All CT acquisitions provided sufficient image quality allowing precise annulus measurements. Mean attenuation (p < 0.001) and image noise (p = 0.01) were higher in the free-breathing group, while image quality was comparable (p = 0.36). The agreement rate between CT-suggested valve size and THV implanted size was comparable, estimated at 87% (κ = 0.79, 95%CI 0.566, 0.908) on free-breathing vs. 82% (κ = 0.78, 95%CI 0.634, 0.904) on breath-holding. The procedure was successful for all patients without increase in 30-day mortality or adverse events. CONCLUSIONS: Free-breathing cardiac CTA allows accurate aortic annulus measurements without compromising image quality or patients' outcome after TAVR. Elderly patients experiencing dyspnea, discomfort, or hearing loss that could prevent proper breath-holding should not be excluded from CT prior to TAVR. CLINICAL RELEVANCE STATEMENT: To decrease elderly patients' discomfort, MDCT evaluation prior to transcatheter aortic valve replacement (TAVR) may be performed on quiet breathing with no significant impact on the outcome. KEY POINTS: • Adhering to CT breathing commands can be challenging for patients with dyspnea, hearing impairment, agitation, or pulmonary diseases. • Free-breathing cardiac CT may be an alternative to breath-holding for patients unable to follow the breathing commands. • Wide-detector CT acquisition on free-breathing does not impair annulus measurements and prosthesis sizing in patients scheduled for TAVR.

Balloon Pressure Technique with the Scepter Mini Balloon as Part of the Endovascular Strategy for Brain Arteriovenous Malformations Embolization : Preliminary Multicenter Experience.

BACKGROUND: The balloon pressure technique (BPT) is an alternative to the pressure cooker technique. A dual lumen balloon (DLB) is used to inject the liquid embolic agent through the working lumen while the balloon is inflated. The purpose of our study was to report our early experience using the Scepter Mini dual lumen balloons for BPT in brain arteriovenous malformation (bAVM) embolization. MATERIAL AND METHODS: Consecutive patients treated from July 2020 to July 2021 in 3 tertiary centers using the BPT with low-profile dual lumen balloons (Scepter Mini, Microvention, Tustin, CA, USA) by endovascular means for bAVMs were retrospectively reviewed. Patient demographics and bAVM angio-architectural features were collected. The feasibility of Scepter Mini balloon navigation close to the nidus was evaluated. Technical as well as clinical (ischemic and/or hemorrhagic) complications were also systematically assessed. The occlusion rate was evaluated on follow-up DSA. RESULTS: A total of 19 patients (10 females; mean age = 38.2 years) consecutively treated for a bAVM (8 ruptured/11 unruptured) using the BPT with a Scepter Mini through 23 embolization sessions were included in our series. Navigation of the Scepter Mini was feasible in all cases. Of the patients 3 (16%) had procedure-related ischemic stroke and 2 patients (10.5%) had late hemorrhages. None of these complications led to severe permanent sequela. Complete occlusion of bAVM embolized with intention to cure was recorded in 11/13 cases (84.6%). CONCLUSION: The BPT using low-profile dual lumen balloons is feasible and seems safe for embolization of bAVMs. It may help to reach high occlusion rates, especially when performed in the intent to cure by embolization only.

Persistent flow inside the Woven EndoBridge at angiographic follow-up: A multicenter study.

BACKGROUND: The occurrence of persistent intra-device filling (BOSS 1, using the Bicêtre Occlusion Scale Score (BOSS)) in aneurysms treated with a Woven Endobridge (WEB) device is infrequent based on angiographic follow-up. To date, three monocentric case series were published studying BOSS 1 cases. Through a multicenter retrospective study, we aimed to report the incidence, and risk factors of intra-WEB persistent filling. METHODS: We reached out to European academic centers that treat patients using WEB devices and requested de-identified data of patients treated with a WEB device and underwent angiographic follow-up, at least 3 months after embolization, to assess the BOSS 1 occlusion score. We compared baseline characteristics, treatment modalities, and aneurysm data of the included BOSS 1 patients with those of a control group consisting of non-BOSS 1 patients (n = 116) who had an available angiographic follow-up. Univariable and multivariable models were employed for analysis. RESULTS: Among the pooled sample of 591 aneurysms treated with WEB, the rate of persistent flow (BOSS 1) at angiographic follow-up was 5.2% (n = 31 out of 591), performed after an average of 8.7 ± 6.3 months. In the multivariable-adjusted analysis, dual antiplatelet therapy in the postoperative period (adjusted odds ratio [aOR] 4.3 [95% CI 1.3-14.2]), and WEB undersizing (aOR 10.8 [95% CI 2.9-40]) were independently associated with a BOSS 1 persistent flow result. CONCLUSION: Persistent blood flow within the WEB device during angiographic follow-up (BOSS 1) is an uncommon occurrence. Our findings indicate that post-procedural dual antiplatelet therapy and undersizing of the WEB device are independently associated with the presence of BOSS 1 at follow-up.

"National survey for preliminary evaluation of neuroradiological protocols in patients with infective endocarditis".

OBJECTIVES: The aim of this study was to identify imaging protocols in patients with infective endocarditis through a nationwide survey. METHODS: An electronic evolutionary survey was sent to interventional Neuroradiologists among neuroradiological centers, under the aegis of the Société Française de Neuroradiologie. Among 33 contacted centers, 25 completed the survey (21 universitary hospitals and 4 peripheric hospitals). RESULTS: Most of the centers (88%) used systematic imaging screening in IE patients. MRI was the first imaging method used in 66% of cases, while CT was used in 44%. When no IIA was detectable in CT-scan screening, 6 (54,54%) stopped investigations, while 9 (81,81%) continued with MRI exploration in case of hemorrhage, ischemia or enhancement. Sulcal hemorrhage on MRI was an indication of complementary DSA in 25 centers (100%). Regarding IIA characterization, 12 centers (48%) used systematic DSA, whereas for 10 centers (40%), DSA was conditioned by hemorrhage or patient status. CONCLUSION: We highlighted large variations in Neuroimaging exploration and follow-up of IE patients in real-world practices. Expert guidelines able to standardize practices are warranted to improve the management of this serious and often misdiagnosed pathology.

Endovascular treatment as first-line therapy in Spetzler-Martin grade III brain arteriovenous malformations: a multicenter retrospective study.

OBJECTIVE: The management of Spetzler-Martin grade (SMG) III brain arteriovenous malformations (bAVMs) may be challenging, whatever the exclusion treatment modality chosen. The purpose of this study was to evaluate the safety and effectiveness of endovascular treatment (EVT) as a first-line treatment of SMG III bAVMs. METHODS: The authors performed a retrospective, two-center, observational cohort study. Cases recorded in institutional databases between January 1998 and June 2021 were reviewed. Patients who were ≥ 18 years of age, had ruptured or unruptured SMG III bAVMs, and received EVT as first-line therapy were included. Baseline characteristics of patients and bAVMs, procedure-related complications, clinical outcome according to the modified Rankin Scale, and angiographic follow-up were assessed. The independent risk factors of procedure-related complications and poor clinical outcome were assessed using binary logistic regression. RESULTS: One hundred sixteen patients with 116 SMG III bAVMs were included. The mean age of the patients was 41.9 ± 14.0 years. The most common presentation was hemorrhage (66.4%). Forty-nine (42.2%) bAVMs were found to be completely obliterated by EVT alone at follow-up. Complications occurred in 39 patients (33.6%), including 5 (4.3%) major procedure-related complications. There was no independent predictor of procedure-related complication. Age > 40 years and poor preoperative modified Rankin Scale score were the independent predictors of poor clinical outcome. CONCLUSIONS: EVT of SMG III bAVMs provides encouraging results but needs further improvement. When the embolization procedure performed with intent to cure appears difficult and/or risky, a combined technique (with microsurgery or radiosurgery) may be a safer and more effective strategy. In terms of safety and effectiveness, the benefit of EVT (alone or included in a multimodal management strategy) for SMG III bAVMs needs to be confirmed by randomized controlled trials.

Comparison of three antithrombotic strategies for emergent carotid stenting during stroke thrombectomy: a multicenter study.

BACKGROUND: Periprocedural antithrombotic treatment is a key determinant for the risk-benefit balance of emergent carotid artery stenting (eCAS) during stroke thrombectomy. We aimed to assess the safety and efficacy of three types of antithrombotic treatment. METHODS: Retrospective review of prospectively collected endovascular databases in four comprehensive stroke centers, including consecutive cases of eCAS for tandem lesion strokes between January 2019 and July 2021. During this period, each center prospectively applied one of three periprocedural protocols: (a) two centers administered aspirin (250 mg IV); (b) one center administered aspirin and heparin (bolus+24 hours infusion); and (c) one center applied an aggressive antiplatelet strategy consisting of aspirin and clopidogrel (loading doses), with added intravenous tirofiban if in-stent thrombosis was observed during thrombectomy. Dichotomized comparisons of outcomes were performed between aggressive versus non-aggressive strategy (aspirin±heparin) and aspirin+heparin versus aspirin-alone groups. RESULTS: Among 161 included patients, 62 received aspirin monotherapy, 38 aspirin+heparin, and 61 an aggressive treatment. Aggressive antiplatelet treatment was associated with an increased rate of excellent (modified Thrombolysis in Cerebral Infarction (mTICI) 2c-3) recanalization and reduced carotid stent thrombosis at day 1 (3.5% vs 16.3%), compared with non-aggressive strategy. There were no significant differences in hemorrhagic transformation or 90-day mortality. There was a tendency towards better clinical outcome with aggressive treatment, without reaching statistical significance. Addition of heparin to aspirin was not associated with an increased rate of carotid stent patency. CONCLUSIONS: Aggressive antiplatelet treatment was associated with improved intracranial recanalization and carotid stent patency, without safety concerns. These findings have implications for randomized trials and may be of utility for clinicians when making antithrombotic treatment choices.

Bifurcation geometry remodelling of vessels in de novo and growing intracranial aneurysms: a multicenter study.

BACKGROUND: Geometrical parameters, including arterial bifurcation angle, tortuosity, and arterial diameters, have been associated with the pathophysiology of intracranial aneurysm (IA) formation. The aim of this study was to investigate whether these parameters were present before or if they resulted from IA formation and growth. METHODS: Patients from nine academic centers were retrospectively identified if they presented with a de novo IA or a significant IA growth on subsequent imaging. For each patient, geometrical parameters were extracted using a semi-automated algorithm and compared between bifurcations with IA formation or growth (aneurysmal group), and their contralateral side without IA (control group). These parameters were compared at two different times using univariable models, multivariable models, and a sensitivity analysis with paired comparison. RESULTS: 46 patients were included with 21 de novo IAs (46%) and 25 significant IA growths (54%). The initial angle was not different between the aneurysmal and control groups (129.7±42.1 vs 119.8±34.3; p=0.264) but was significantly wider at the final stage (140.4±40.9 vs 121.5±34.1; p=0.032), with a more important widening of the aneurysmal angle (10.8±15.8 vs 1.78±7.38; p=0.001). Variations in other parameters were not significant. These results were confirmed by paired comparisons. CONCLUSION: Our study suggests that wider bifurcation angles that have long been deemed causal factors for IA formation or growth may be secondary to IA formation at pathologic bifurcation sites. This finding has implications for our understanding of IA formation pathophysiology.

Antithrombotic therapies for neurointerventional surgery: a 2021 French comprehensive national survey.

BACKGROUND: Neurointerventionists lack guidelines for the use of antithrombotic therapies in their clinical practice; consequently, there is likely to be significant heterogeneity in antithrombotic use between centers. Through a nationwide survey, we aimed to obtain an exhaustive cross-sectional overview of antithrombotic use in neurointerventional procedures in France. METHODS: In April 2021, French neurointerventional surgery centers were invited to participate in a nationwide 51-question survey disseminated through an active trainee-led research collaborative network (the JENI-RC). RESULTS: All 40 centers answered the survey. Fifty-one percent of centers reported using ticagrelor and 43% used clopidogrel as premedication before intracranial stenting. For flow diversion treatment, dual antiplatelet therapy was maintained for 3 or 6 months in 39% and 53% of centers, respectively, and aspirin was prescribed for 12 months or more than 12 months in 63% and 26% of centers, respectively. For unruptured aneurysms, the most common heparin bolus dose was 50 IU/kg (59%), and only 35% of centers monitored heparin activity for dose adjustment. Tirofiban was used in 64% of centers to treat thromboembolic complications. Fifteen percent of these comprehensive stroke centers reported using tenecteplase to treat acute ischemic strokes. Cangrelor appeared as an emergent drug in specific indications. CONCLUSION: This nationwide survey highlights the important heterogeneity in clinical practices across centers. There is a pressing need for trials and guidelines to further evaluate and harmonize antithrombotic regimens in the neurointerventional field.

The human placenta as a model for training and research in mechanical thrombectomy: Clarifications and use of the chorionic plate veins.

Indications for mechanical thrombectomy in acute ischemic stroke are increasing, resulting in the continuous development of new devices and techniques. Therefore, there is a need for a realistic testing and training environment that offers the opportunity to practice different procedures and test the latest devices. Some authors have described the use of the human placenta as a model for neurointerventional surgery, with striking similarities to real-life conditions. This model has many advantages, including its relatively low cost and minimal infrastructure requirements, with fewer ethical concerns compared to animal models. So far, some preparation and set-up details were missing, and only arteries from the chorionic plate were used. This article provides the necessary clarifications and a mapping of the chorionic plate veins, so that the use of this model, which is particularly well suited for mechanical thrombectomy, can be as easy and wide as possible. A video explaining how to prepare the model is provided.

Surgery for lung cancer: postoperative changes and complications-what the Radiologist needs to know.

Imaging findings after thoracic surgery can be misleading. Knowledge of the normal post-operative anatomy helps the radiologist to recognise life-threatening complications and conversely not to wrongly evoke a complication in cases of trivial post-operative abnormalities. In this educational article, we reviewed the expected patterns after thoracic surgery including sublobar resection, lobectomy, pneumonectomy and related techniques. Imaging aspects of frequent and less common complications and their typical imaging features are then presented.