Osbun, Joshua W

OBJECTIVE Cognard type V dural arteriovenous fistulas (dAVFs), defined by spinal perimedullary venous drainage, represent a rare and aggressive neurovascular pathology. Comprehensive multicenter data remain scarce. The authors present the largest multicenter analysis to date, characterizing presentation, radiology, treatment, complications, and functional outcomes of Cognard type V dAVFs. METHODS The authors retrospectively analyzed patients with angiographically confirmed Cognard type V dAVFs from the Consortium for Dural Arteriovenous Fistula Outcomes Research (CONDOR), spanning 16 academic centers. Patient demographics, imaging features, treatment strategies, procedural complications, and modified Rankin Scale (mRS) scores were recorded. RESULTS Among 1077 patients with dAVFs, 37 (3%) had Cognard type V lesions. The mean patient age was 57 years, and 59.5% of patients were male. Most presented with nonhemorrhagic neurological deficits (68%), while 14% had hemorrhage. The most common location was the foramen magnum (32%). Embolization was the primary treatment in 67% of cases, complete obliteration was achieved in 71% of cases. Upfront microsurgery was performed in 22% of patients (obliteration rate 88%), and radiosurgery in 14% (success rate 40%). Salvage treatment further improved obliteration outcomes. Temporary complications occurred in 8% of patients (3/37): 2 with transient neurological deficits postembolization and 1 with transient hydrocephalus after surgery. Permanent complications were observed in 3% (1/37) due to treatment-related hemorrhage. At the last follow-up (mean 2.4 years), 69% (24/35) of patients maintained or improved to an mRS score ≤ 2. No deaths occurred. Functional improvement was seen in 29% (10/35), while mRS decline was in 40% of patients (14/35), all unrelated to the dAVF itself. CONCLUSIONS Cognard type V dAVFs carry a high risk of neurological morbidity. However, favorable functional outcomes are achievable with timely, multimodal intervention. Complication rates remain low, with most being transient. These data support aggressive but tailored management to prevent permanent disability in this high-risk population.

BACKGROUND: Hemorrhagic risk in dural arteriovenous fistulas (dAVFs) is largely determined by venous anatomy, but the contribution of systemic cardiovascular factors and their medical therapy remains poorly defined. This study examined associations between cardiovascular risk factors and antithrombotic use and hemorrhagic presentation, angiographic obliteration, and early functional outcomes after treatment. METHODS: We analyzed 1350 adults with intracranial dAVFs from the international Consortium for Dural Arteriovenous Fistula Outcomes Research registry, which retrospectively accrued cases across 14 centers in 4 countries between 1990 and 2017. Demographics, cardiovascular comorbidities, antithrombotic use, angioarchitectural features, treatment strategies, and follow-up outcomes were collected from prospectively maintained databases. Primary end points were hemorrhagic presentation, angiographic obliteration, and 90-day functional status after treatment. Univariable and multivariable logistic regressions were performed with model-specific adjustments. RESULTS: Hemorrhage occurred in 375 patients (27.8%) and was most strongly associated with high-grade dAVF classification and male sex; antithrombotic therapy was associated with lower odds of hemorrhagic presentation. Other cardiovascular risk factors showed no independent relationship with bleeding. Angiographic obliteration was achieved in 621 of 845 patients (73.5%). Hemorrhagic onset, high dAVF grade, and surgical treatment were independently associated with angiographic obliteration, whereas smoking and embolization demonstrated only nonsignificant trends after adjustment. At 90 days, 934 patients (88.9%) were functionally independent. Baseline modified Rankin Scale score was the strongest factor associated with 90-day functional outcome, while neither cardiovascular comorbidities nor treatment modality independently influenced functional status. CONCLUSIONS: In this large multicenter dAVF cohort, hemorrhagic presentation was most strongly associated with venous angioarchitecture. Male sex and antithrombotic therapy were also independently associated with hemorrhagic presentation. Angiographic obliteration was common, particularly among surgically treated lesions, and 90-day functional outcome was most strongly associated with baseline functional status.

OBJECTIVE Dural arteriovenous fistulas (dAVFs) are rare cerebrovascular anomalies. Tentorial dAVFs (TDAVFs) have more aggressive features, making them prone to symptomatic presentations and hemorrhage. TDAVFs are heterogenous and require tailored surgical approaches. Presented is a multicenter analysis of TDAVF surgical outcomes. METHODS The Consortium for Dural Arteriovenous Fistula Outcomes Research (CONDOR) consortium compiled data on dAVFs from 16 international centers from 1990 to 2021 retrospectively. Microsurgical treatment success was defined as angiographically confirmed complete obliteration of the fistula or discontinuation of cortical venous drainage (CVD) in high-grade TDAVFs. TDAVF subtypes and tailored surgical approaches were reviewed. RESULTS Of 1360 patients in CONDOR, 161 had TDAVFs and 27% (44/161) of these patients underwent surgical management, with the majority (52% [23/44]) receiving surgery as a salvage treatment following failed embolization. The mean age (SD) of this cohort was 56 (15) years, and 68% (30/44) were male. In total, 91% (40/44) of surgically treated patients presented with aggressive symptoms: 64% (28/44) presented with hemorrhage and 27% (12/44) with nonhemorrhagic neurological deficit (NHND). The median (IQR) duration from symptom onset to diagnosis was 1 (1–4) day. The median time (IQR) between diagnosis and surgery was 15 (3–80) days. Surgical approaches varied across the cohort, with the retrosigmoid being the most common (44% [18/41]), followed by the midline suboccipital (24% [10/41]) and occipital (15% [6/41]) approaches. Perioperative complications occurred in 11% (5/44) of cases, as well as permanent neurological deficits in 2% (1/44). Surgical success was achieved in 90% of patients (38/42). During the mean 3-year follow-up, 2 patients experienced a recurrence of their fistula including representation of CVD (2/38 [5%]) and 1 patient had a new NHND (1/43 [2%]). Shorter symptom duration was significantly associated with success (15.6 vs 181.5 days, p = 0.001). Primary versus salvage microsurgery showed no difference in outcomes. Both patients with recurrent fistula were effectively treated with Gamma Knife radiosurgery. CONCLUSIONS Resection is safe and durable for the treatment of TDAVF not otherwise amenable to embolization. It can achieve a high degree of success with a low rate of perioperative complications and permanent neurological deficits, benefits far exceeding the risks associated with TDAVF natural history or management with less effective modalities.

Abstract Background Recent trials have furthered uncertainty regarding the endovascular benefit for medium vessel occlusions (MeVO). Stent retrievers (SR) were employed in the first attempt in most interventional arm participants. We sought to compare outcomes in acute MCA M2 occlusions between frontline aspiration and SR, and to delineate procedural and anatomical covariates associated with differential treatment effect. Methods Retrospective analysis of a multicenter stroke thrombectomy cohort identified cases of MT for M2 occlusions. Unmatched and propensity score-matched (PSM) cohorts were generated comparing frontline aspiration to standalone and combined SR. The primary outcome was functional independence (mRS 0–2) at 90 days. Recanalization, symptomatic intracranial hemorrhage (sICH), mortality, and the effect of M2 laterality, division occlusion and procedure time were assessed. Results About 1734 patients with M2 occlusions underwent either frontline aspiration (n = 711) or SR/combined (n = 958) thrombectomy between 2013 and 2024. PSM analysis favored aspiration for functional independence (49.9% vs 44.0%, OR 1.27 (1.03–1.57)), complete recanalization (61.2% vs 48.7%, OR 1.66 (1.34–2.05)), complete first pass effect (35.0% vs 27.6%, OR 1.42 (1.13–1.78)), and sICH (3.5% vs 6.2%, OR 0.55 (0.33–0.91)), with no difference in mortality. Frontline aspiration had significantly shorter procedural times (median 28 [IQR 15–49.5] vs 51 [IQR 35–78] minutes; p < 0.001). For every minute increase in procedure time, the probability of functional independence decreased significantly (p < 0.001) less with frontline aspiration (0.35%) compared to SR/combined (1.61%). Conclusion Frontline aspiration for M2 occlusions resulted in better clinical and angiographic outcomes compared to SRs. Future trials for MeVO with a focus on contact aspiration thrombectomy may succeed where recent trials have failed.

Background Endovascular thrombectomy (EVT) has transformed acute ischemic stroke (AIS) care, with onset-to-puncture (OTP) time widely recognized as a critical determinant of outcome. However, emerging evidence suggests that in-hospital procedure time (PT)—from arterial puncture to final recanalization—may have an equally or more significant impact. This study examines the relative contribution of PT versus OTP to functional outcomes in patients with AIS undergoing EVT. Methods A retrospective analysis was conducted of 6644 patients with AIS treated at 44 international stroke centers from the Stroke Thrombectomy and Aneurysm Registry (STAR; 2016–2023). Multivariable regression, time-equivalence analysis, and marginal effects modeling were used to assess associations between PT, OTP, and 90-day modified Rankin Scale (mRS) outcomes. Centers were stratified by procedural efficiency and compared using propensity score matching (PSM). Mediation analysis evaluated whether PT accounted for inter-center differences. Results PT and OTP were independently associated with functional outcomes; however, PT had a significantly stronger effect (adjusted OR for mRS 0–2: PT=0.56 vs OTP=0.96 per hour). Each 5 min increase in PT was equivalent to 78–100 min of additional OTP in outcome impact. Centers with faster average PT had higher rates of functional independence (number needed to treat (NNT)=10), fewer complications, and lower symptomatic intracranial hemorrhage rates. PT significantly mediated the relationship between center tier and outcomes (Sobel’s P<0.001). Conclusion While minimizing OTP remains important, PT exerts a greater influence on outcomes after EVT. Procedural efficiency should be emphasized in stroke systems of care and included in center performance metrics to improve patient outcomes.

BACKGROUND AND OBJECTIVES: Flow-diverting stents (FDSs) have improved treatment options for intracranial aneurysms. Although FDS have proven successful in treating aneurysms that would previously have required complex microsurgical or endovascular repairs, treatment failures remain a concern. In this multicenter study, we aim to analyze the predictors of residual aneurysmal filling at early angiographic follow-up. METHODS: A retrospective analysis of a prospectively maintained neuroendovascular database at 14 high-volume US centers was conducted for all patients who underwent FDS placement for intracranial aneurysms between 2011 and 2019. Aneurysms were graded on the O'Kelly-Marotta scale (OKM). RESULTS: A total of 2277 patients underwent FDS embolization for intracranial aneurysms during the study period. The patient's mean age was 55 (SD ± 13.5) years, and 82% were female. The median maximal aneurysm diameter was 6.7 mm (IQR 4.10-11 mm). Complete aneurysm obliteration (OKM grade 4) occurred in 1109 patients (68%), and 146 (9%) were OKM grade 3, 188 (12%) were OKM grade 2, and 174 (11%) were OKM grade 1. In the adjusted multivariate analysis, individuals in the 65-74 years and 75+ years age groups had significantly increased risk of residual aneurysm filling at 6-month follow-up compared with the 18-44 years age group (odds ratio [OR] 1.92 (95% CI: 1.33-2.78) and 2.92 (95% CI: 1.79-4.77), respectively). Aneurysms arising from the superior cerebellar artery, the basilar artery, and the carotid terminus were more likely to have a residual filling (OR 12.6, 95% CI: 1.39–14.7; OR 4.27, 95% CI: 1.39–14.7; OR 3.16, 95% CI: 1.24–8.06, respectively). CONCLUSION: As the utilization of FDS for intracranial aneurysms becomes more widespread, the efficacy of aneurysm obliteration needs to be assessed. Our results indicate that several patient-dependent factors, such as age, aneurysm location, and size, predict the likelihood of residual aneurysm filling 6 months post-treatment.

Introduction: Endovascular thrombectomy (EVT) is an effective treatment for basilar artery occlusion (BAO) stroke in select patients. While there is a growing body of literature suggesting that advanced imaging modalities such as computed tomography perfusion (CTP) and magnetic resonance (MR) may not be necessary for selecting anterior circulation large vessel occlusion stroke patients for EVT, whether advanced imaging may be superior to conventional imaging (non-contrast CT and CT angiography) in identifying good treatment candidates among BAO patients is less clear. Patients and methods: This was a multicenter retrospective cohort study of BAO EVT patients treated from 2013 to 2022 in the Stroke Thrombectomy and Aneurysm Registry. Patients selected for EVT by advanced imaging (CTP or MR) were matched with those selected by conventional imaging using propensity score matching (PSM) accounting for possible confounders. Primary outcome was functional independence at 90 days. Other outcomes include bedridden state or death at 90-days and symptomatic intracranial hemorrhage (sICH). Results: 268 patients were included. 150 patients were selected for BAO EVT by conventional imaging, 86 by CTP, and 32 by MR. Patients selected by advanced imaging were significantly older than those selected by conventional imaging (median age 71 vs 64 years, p = 0.001); patient characteristics were otherwise similar between cohorts. After PSM, 90-day outcomes were similar between the two cohorts ( p = 0.56), with similar rates of functional independence (39.4% vs 35.1%, p = 0.65), bedridden state or death (40.4% vs 44.7%, p = 0.66), and sICH (3.3% vs 5.7%, p = 0.49) for conventional and advanced imaging groups, respectively. Results were similar across treatment time windows (all p > 0.05). Conclusions: Selecting patients for basilar EVT using conventional versus advanced imaging did not result in different clinical outcomes, regardless of treatment time windows. Conventional imaging appears sufficient as a first-line tool for selecting basilar EVT patients in routine clinical practice.

Background The effectiveness of endovascular thrombectomy (EVT) for low Alberta Stroke Program Early CT score (ASPECTS) stroke patients with occlusion of the second segment of the middle cerebral artery (M2) is unclear. Methods This was a multicenter retrospective study. Patients with M1 or M2 occlusions and low ASPECTS (<6) who underwent successful EVT (modified treatment in cerebral ischemia score of 2b or higher) were included. Primary outcome was futile EVT reperfusion (defined as 90-day modified Rankin scale of 5 or 6). Other outcomes of interest include acceptable outcomes (modified Rankin scale of 3 or less) and intracranial hemorrhage (ICH), and all-cause 90-day mortality. Outcomes for M1 patients were compared to M2 patients with multivariable logistic regression models accounting for potential confounders. Results 173 patients with M1 or M2 occlusions and low ASPECTS (<6) who underwent successful EVT were identified. After multivariable adjustments, M2 patients had significantly higher odds of futile reperfusion (OR 5.48 [95%CI 1.91 to 15.7], p = 0.002), lower odds of acceptable outcomes (OR 0.33 [95%CI 0.12 to 0.89], p = 0.028), and higher odds of all-cause mortality (OR 4.90 [95%CI 1.65 to 14.5], p = 0.004). These findings suggest that EVT's efficacy for low-ASPECTS stroke patients may be diminished for patients with M2 occlusions. M2 occlusion was not significantly associated with ICH. Conclusions Among low-ASEPCTS stroke patients who underwent successful EVT, those with M2 occlusions had significantly higher odds of poor outcome compared to those with M1 occlusions.