The benefit of reperfusion therapies for acute ischemic stroke decreases over time. This decreasing benefit is presumably due to the disappearance of salvageable ischemic brain tissue (ie, the ...penumbra).
To study the association between stroke onset-to-imaging time and penumbral volume in patients with acute ischemic stroke with a large vessel occlusion.
A retrospective, multicenter, cross-sectional study was conducted from January 1, 2015, to June 30, 2022. To limit selection bias, patients were selected from (1) the prospective registries of 2 comprehensive centers with systematic use of magnetic resonance imaging (MRI) with perfusion, including both thrombectomy-treated and untreated patients, and (2) 1 prospective thrombectomy study in which MRI with perfusion was acquired per protocol but treatment decisions were made with clinicians blinded to the results. Consecutive patients with acute stroke with intracranial internal carotid artery or first segment of middle cerebral artery occlusion and adequate quality MRI, including perfusion, performed within 24 hours from known symptoms onset were included in the analysis.
Time from stroke symptom onset to baseline MRI.
Penumbral volume, measured using automated software, was defined as the volume of tissue with critical hypoperfusion (time to maximum >6 seconds) minus the volume of the ischemic core. Substantial penumbra was defined as greater than or equal to 15 mL and a mismatch ratio (time to maximum >6-second volume/core volume) greater than or equal to 1.8.
Of 940 patients screened, 516 were excluded (no MRI, n = 19; no perfusion imaging, n = 59; technically inadequate perfusion imaging, n = 75; second segment of the middle cerebral artery occlusion, n = 156; unwitnessed stroke onset, n = 207). Of 424 included patients, 226 (53.3%) were men, and mean (SD) age was 68.9 (15.1) years. Median onset-to-imaging time was 3.8 (IQR, 2.4-5.5) hours. Only 16 patients were admitted beyond 10 hours from symptom onset. Median core volume was 24 (IQR, 8-76) mL and median penumbral volume was 58 (IQR, 29-91) mL. An increment in onset-to-imaging time by 1 hour resulted in a decrease of 3.1 mL of penumbral volume (β coefficient = -3.1; 95% CI, -4.6 to -1.5; P < .001) and an increase of 3.0 mL of core volume (β coefficient = 3.0; 95% CI, 1.3-4.7; P < .001) after adjustment for confounders. The presence of a substantial penumbra ranged from approximately 80% in patients imaged at 1 hour to 70% at 5 hours, 60% at 10 hours, and 40% at 15 hours.
Time is associated with increasing core and decreasing penumbral volumes. Despite this, a substantial percentage of patients have notable penumbra in extended time windows; the findings of this study suggest that a large proportion of patients with large vessel occlusion may benefit from therapeutic interventions.
Background
International dose reference levels are lacking for mechanical thrombectomy in acute ischemic stroke patients with large vessel occlusions. We studied whether radiation dose-reduction ...systems (RDS) could effectively reduce exposure and propose achievable levels.
Materials and methods
We retrospectively included consecutive patients treated with thrombectomy on a biplane angiography system (BP) in five international, high-volume centers between January 2014 and May 2017. Institutional Review Board approvals were obtained. Technical, procedural, and clinical characteristics were assessed. Efficacy, safety, radiation dose, and contrast load were compared between angiography systems with and without RDS. Multivariate analyses were adjusted according to Bonferroni’s correction. Proposed international achievable cutoff levels were set at the 75th percentile.
Results
Out of the 1096 thrombectomized patients, 520 (47%) were treated on a BP equipped with RDS. After multivariate analysis, RDS significantly reduced dose–area product (DAP) (91 vs 140 Gy cm
2
, relative effect 0.74 (CI 0.66; 0.83), 35% decrease,
p
< 0.001) and air kerma (0.46 vs 0.97 Gy, relative effect 0.63 (CI 0.56; 0.71), 53% decrease,
p
< 0.001) with 75th percentile levels of 148 Gy cm
2
and 0.73 Gy, respectively. There was no difference in contrast load, rates of successful recanalization, complications, or clinical outcome.
Conclusion
Radiation dose-reduction systems can reduce DAP and air kerma by a third and a half, respectively, without affecting thrombectomy efficacy or safety. The respective thresholds of 148 Gy cm
2
and 0.73 Gy represent achievable levels that may serve to optimize current and future radiation exposure in the setting of acute ischemic stroke treatment. As technology evolves, we expect these values to decrease.
Key Points
• Internationally validated achievable levels may help caregivers and health authorities better assess and reduce radiation exposure of both ischemic stroke patients and treating staff during thrombectomy procedures.
• Radiation dose-reduction systems can reduce DAP and air kerma by a third and a half, respectively, without affecting thrombectomy efficacy or safety in the setting of acute ischemic stroke due to large vessel occlusion.
Determining the mechanism of large vessel occlusion related acute ischemic stroke is of major importance to initiate a tailored secondary prevention strategy. We investigated using the ...atherosclerosis, small vessel disease, cardiac source, other cause, dissection (ASCOD) classification the distribution of the causes of large vessel occlusion related acute ischemic stroke treated by mechanical thrombectomy.
This was a predefined substudy of the FRAME (French Acute Multimodal Imaging to Select Patient for Mechanical Thrombectomy). Each patient underwent a systematic etiological workup including brain and vascular imaging, electrocardiogram monitoring lasting at least 24 hours and routine blood tests. Stroke mechanisms were systematically evaluated using the atherosclerosis, small vessel disease, cardiac source, other cause, dissection grading system at 3 months. We defined single potential cause by one cause graded 1 in a single domain, possible cause as a cause graded 1 or 2 regardless of overlap, and no identified cause without grade 1 nor 2 causes.
A total of 215 patients (mean age 70±14; 50% male) were included. A single potential cause was identified in 148 (69%). Cardio-embolism (53%) was the most frequent, followed by atherosclerosis (9%), dissection (5%) and other causes (1%). Atrial fibrillation accounted for 88% of C1. Overlap between grade 1 causes was uncommon (3%). Possible causes were identified in 168 patients (83%) and 16 (7%) had no cause identified after the initial evaluation.
Cardio-embolism, especially atrial fibrillation, was the major cause of large vessel occlusion related acute ischemic stroke. This finding emphasizes the yield of paroxysmal atrial fibrillation detection in those patients. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03045146.
Background
The composition of the thrombus influences its retrievability by mechanical thrombectomy.
Purpose
Our study aimed to report on thrombi resistant to aspiration, regarding susceptibility ...vessel sign and histologic composition.
Methods
This observational study was based on a prospective database of acute anterior circulation ischemic strokes treated by mechanical thrombectomy. Endovascular first-line strategy was aspiration and in case of failure, combined therapy-rescue was performed. The positivity of susceptibility vessel sign (SVS+) or its negativity (SVS−) was assessed on T2* sequences. The thrombus composition was analyzed with hematoxylin eosin staining.
Results
Histological analysis was performed on 102 clots. Thrombi with SVS− were significantly richer in fibrin/platelets, p = 0.04. Out of 210 mechanical thrombectomy, aspiration first pass strategy was performed in 131/210 (62%) patients. Combined therapy-rescue was needed in 37% of aspiration first pass strategy cases (n = 131). Clots retrieved combined therapy-rescue were richer in fibrin/platelets 63.9% versus 50.8% for aspiration first pass strategy, p = 0.03. Logistic regression analysis showed that fibrin/platelet-poor clots (<60%) were significantly more likely to be recanalized by aspiration first pass strategy compared to fibrin/platelet-rich clots (>60%) that were more likely recanalized by combined therapy-rescue after aspiration first pass strategy failure (OR = 3.5; 95% CI = 1.2–10.8; p = 0.0054).
Conclusions
Our results confirm that SVS− clots are rich in fibrin/platelets and suggest that these “white clots” are less likely to be retrieved by aspiration alone and more often require the use of combined therapy.
To report the morbidity and long term results in the treatment of paragangliomas by transarterial embolization with ethylene vinyl alcohol (Onyx), either as preoperative or palliative treatment.
...Between September 2005 and 2012, 18 jugulotympanic, 7 vagal, and 4 carotid body paragangliomas (CBPs) underwent Onyx embolization, accordingly to our head and neck multidisciplinary team's decision. CBPs were embolized preoperatively. Jugulotympanic and vagal paragangliomas underwent surgery when feasible, otherwise palliative embolization was carried out alone, or in combination with radiotherapy or tympanic surgery in the case of skull base or tympanic extension. Treatment results, and clinical and MRI follow-up data were recorded.
In all cases, devascularization of at least 60% of the initial tumor blush was obtained; 6 patients underwent two embolizations. Post-embolization, 8 patients presented with cranial nerve palsy, with partial or complete regression at follow-up (mean 31 months, range 3-86 months), except for 2 vagal and 1 hypoglossal palsy. 10 patients were embolized preoperatively; 70% were cured after surgery and 30% showed residual tumor. 19 patients received palliative embolization, of whom 5 underwent radiotherapy and 3 received tympanic surgery post-embolization. Long term follow-up of palliative embolization resulted in tumor volume stability (75%) or extension in intracranial or tympanic compartments. Onyx embolization of CBPs resulted in more difficult surgical dissection in 2 of 4 cases.
Onyx embolization is a valuable alternative to surgery in the treatment of jugulotympanic and vagal paragangliomas; tympanic surgery or radiosurgery of the skull base should be considered in selected cases. Preoperative Onyx embolization of CBPs is not recommended.
Choice of anesthesia type on outcome for mechanical thrombectomy (MT) in acute ischemic stroke remains controversial. The goal of our research was to study the impact of anesthesia strategy on the ...delay, angiographic and neurological outcome of MT performed under general anesthesia (GA) vs. conscious sedation (CS).
This prospective, single-center observational study included patients with anterior circulation large vessel occlusion (ACLVO) strokes treated with MT within 6 hours of symptom onset. All time metrics were evaluated. Angiographic and clinical outcomes were assessed by recanalization rate (mTICI) and 3-month functional independence (mRs). Complications and mortality rate were recorded as safety outcomes.
In total, 303 consecutive thrombectomies were performed, 86.8% under GA. NIHSS was higher in GA, with median of 19.0 for GA and 16.5 for CS (P = 0.049). Median time from arrival in hospital (door) to groin puncture was 83 min (IQR = 45.0–109.5) for GA compared to 72 min (IQR = 35.0–85.3) for CS, P = 0.170). Median time from arrival in the angiosuite to groin puncture was 20 min (IQR = 15.0–29.0) for GA compared to 15 min (IQR = 10.0–20.0) for CS, P = 0.017). There were no significant differences in recanalization time metrics, successful revascularization rate, functional independence and mortality rate at three months.
GA induced a 5 to 10 minutes delay for groin puncture, without impact on recanalization time metrics, or neurological outcome at 3 months. Our results demonstrate that a well-organized workflow is associated with reasonable delay in performing GA for MT, without effect on outcome compared to sedation.
Several studies have shown promising outcomes of the Woven EndoBridge (WEB) device for the treatment of wide-necked intracranial bifurcation aneurysms. This is a multicenter study attempts to explore ...the changes in trends and treatment outcomes over time for WEB embolization of intracranial aneurysms. The WorldWideWEB consortium is a retrospective multicenter collaboration of data from international centers spanning from January 2011 and June 2021, with no limitations on aneurysm location or rupture status. Both bifurcation and sidewall aneurysms were included. These patients were stratified based on treatment year into five treatment intervals: 2011–2015 (
N
= 66), 2016–2017 (
N
= 77), 2018 (
N
= 66), 2019 (
N
= 300), and 2020–2021 (
N
= 173). Patient characteristics and angiographic and clinical outcomes were compared between these time intervals. This study comprised 671 patients (median age 61.4 years; 71.2% female) with 682 intracranial aneurysms. Over time, we observed an increasing tendency to treat patients presenting with ruptured aneurysms and aneurysms with smaller neck, diameter, and dome widths. Furthermore, we observed a trend towards more off-label use of the WEB for sidewall aneurysms and increased adoption of transradial access for WEB deployment. Moreover, the proportion of patients with adequate WEB occlusion immediately and at last follow-up was significantly higher in more recent year cohorts, as well as lower rates of compaction and retreatment. Mortality and complications did not differ over time. This learning curve study suggests improved experience using the WEB for the treatment of intracranial aneurysms and has yielded higher rates of adequate occlusion over time.
The Woven EndoBridge (WEB) device has been widely used to treat intracranial wide neck bifurcation aneurysms. Initial studies have demonstrated that approximately 90% of patients have same or ...improved long-term aneurysm occlusion after the initial 6-month follow up. The aim of this study is to assess the long-term follow-up in aneurysms that have achieved complete occlusion at 6 months. We also compared the predictive value of different imaging modalities used. This is an analysis of a prospectively maintained database across 13 academic institutions. We included patients with previously untreated cerebral aneurysms embolized using the WEB device who achieved complete occlusion at first follow-up and had available long-term follow-up. A total of 95 patients with a mean age of 61.6 ± 11.9 years were studied. The mean neck diameter and height were 3.9 ± 1.3 mm and 6.0 ± 1.8 mm, respectively. The mean time to first and last follow-up was 5.4 ± 1.8 and 14.1 ± 12.9 months, respectively. Out of all the aneurysms that were completely occluded at 6 months, 84 (90.3%) showed complete occlusion at the final follow-up, and 11(11.5%) patients did not achieve complete occlusion. The positive predictive value (PPV) of complete occlusion at first follow was 88.4%. Importantly, this did not differ between digital subtraction angiography (DSA), magnetic resonance angiography (MRA), or computed tomography angiography (CTA). This study underlines the importance of repeat imaging in patients treated with the WEB device even if complete occlusion is achieved short term. Follow-up can be performed using DSA, MRA or CTA with no difference in positive predictive value.
Aneurysm recanalization concomitant to endo-saccular device (WEB) compaction has been reported. Association of compaction and aneurysm remnant is still discussed in literature. Effect of WEB ...oversizing on compaction and recanalization rates remains unknown.
To assess the association of WEB compaction and risk of aneurysmal remnant.
To assess the association of oversized WEB with complete aneurysmal occlusion, peri-procedural complication, WEB compaction.
We retrospectively included all patients treated with the WEB in our center between March 2012 and August 2018 from a prospectively maintained registry. Review Board approval was obtained. From February 2015 to August 2018, we used the oversizing technique (increase of the WEB width of 1mm compared to aneurysmal width). First we analyzed the association between compaction and occlusion rates. We then compared patients before and after this technical shift, as long as patients with and without “>1 oversized WEB” (oversizing>1mm) for peri-procedural complication, device compaction, complete and adequate occlusion, at 3 to 6 months, 12 to 18 months and after 24 months follow-up (FU). Statistical analyses were performed.
We treated 78 aneurysms in 77 patients. In case of compaction, patients had a lower rate of adequate (91% vs 52%, P=0.005) and complete occlusion (36% vs. 16% P=0.05). The oversizing technique led to improved rates of no-compaction (36 vs. 18%), complete occlusion (28 vs. 13%) at last follow-up despite no statistical significance. For “>1 oversized WEB”, per-procedure complication rate was 3 times higher despite being non-statistically significant (P=0.07). At last follow-up, no-compaction risk was improved (48 vs. 21%, P=0.02) but complete and adequate final occlusion rates were not different.
WEB compaction is associated with increased rates of aneurysm remnants. WEB oversizing may improve the complete occlusion rate whereas decreasing WEB compaction. A too much oversizing may lead to increase the risk of per-procedure complication whereas no additional effect on aneurysmal occlusion.
Rate of adequate occlusions remains acceptable.
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