Little information is available regarding technical challenges with the new lower profile Woven EndoBridge (WEB 17) system intended for smaller aneurysms.
We report illustrative cases of technical ...complications encountered with 2 anterior communicating artery aneurysms treated by the WEB 17 system requiring rescue stenting in both cases, discussing technical nuances regarding potential reasons for the encountered failures along with management plan.
Over a span of 1 year (January 2021 to January 2022), 45 WEB embolization procedures were performed at 2 institutions. Two procedures were complicated by abrupt change in orientation of the WEB device immediately after detachment from the delivery wire. In the first case, abrupt angulation with subsequent migration and prolapse out of the aneurysm sac into the distal right anterior cerebral artery was encountered with unsuccessful retrieval despite multiple attempts using a variety of devices, eventually requiring rescue stenting. A similar sudden orientation change was noted in the second case with partial prolapse from the aneurysm sac similarly bailed out by intracranial stenting. Both patients recovered to preprocedural baseline with no permanent deficits and eventually were discharged home.
Intrasaccular WEB 17 embolization may be technically challenging in smaller wide-necked aneurysms with acute aneurysm–parent artery angulation with abrupt changing of WEB device orientation after detachments with device migration and prolapse into the parent vessel requiring rescue stenting. Proper WEB 17 device sizing and vigilance in the transition phase between the end of deployment and detachment windows of the procedure are paramount to treatment success. Routine use of antiplatelets in cases of anatomical aneurysms that are anticipated to be challenging might be a useful strategy if bailout stenting is needed.
Stereotactic radiosurgery (SRS) of larger arteriovenous malformations (AVM) is associated with an elevated incidence of adverse radiation effects (ARE). To date, volume-response and dose-response ...models have been used to predict such effects. To understand radiological outcomes and their hemodynamic effects on the regional brain.
A retrospective analysis was conducted at our institution using a prospective registry of patients managed between 2014 and 2020. We included patients with AVM with a nidus larger than 5 cc who received either single-session or volume-staged Gamma Knife radiosurgery. AVM volume changes, volumes of parenchymal response, and obliteration were analyzed and correlated with transit times and diameters of feeding arteries and draining veins.
Sixteen patients underwent single-session SRS, and 9 patients underwent volume-staged SRS. The average AVM volume was 12.6 cc (5.5-23). The AVM locations were predominantly lobar (80%) and 17 (68%) were in critical locations. The mean margin dose was 17.2 Gy (15-21), and the median V12Gy was 25.5 cc. Fourteen (56%) AVMs had a transit time shorter than 1 second. The median vein-artery ratio (sum diameter of the veins/sum diameter of feeding arteries) was 1.63 (range, 0.60-4.19). Asymptomatic parenchymal effects were detected in 13 (52%) patients and were symptomatic in 4 (16%) patients. The median time to ARE was 12 months (95% CI 7.6-16.4). On univariate analysis, significant predictors of ARE were lower vein-artery ratio ( P = .024), longer transit time ( P = .05), higher mean dose ( P = .028), and higher D95 ( P = .036).
Transit times and vessel diameters are valuable predictors of the subsequent parenchymal response after SRS. A more quantitative understanding of blood flow is critical for predicting the effects on the regional brain after AVM radiosurgery.
Morphological and angioarchitectural features of cerebral arteriovenous malformations (AVMs) have been widely described and associated with outcomes; however, few studies have conducted a ...quantitative analysis of AVM flow. The authors examined brain AVM flow and transit time on angiograms using direct visual analysis and a computer-based method and correlated these factors with the obliteration response after Gamma Knife radiosurgery.
A retrospective analysis was conducted at a single institution using a prospective registry of patients managed from January 2013 to December 2019: 71 patients were analyzed using a visual method of flow determination and 38 were analyzed using a computer-based method. After comparison and validation of the two methods, obliteration response was correlated to flow analysis, demographic, angioarchitectural, and dosimetric data.
The mean AVM volume was 3.84 cm3 (range 0.64-19.8 cm3), 32 AVMs (45%) were in critical functional locations, and the mean margin radiosurgical dose was 18.8 Gy (range 16-22 Gy). Twenty-seven AVMs (38%) were classified as high flow, 37 (52%) as moderate flow, and 7 (10%) as low flow. Complete obliteration was achieved in 44 patients (62%) at the time of the study; the mean time to obliteration was 28 months for low-flow, 34 months for moderate-flow, and 47 months for high-flow AVMs. Univariate and multivariate analyses of factors predicting obliteration included AVM nidus volume, age, and flow. Adverse radiation effects were identified in 5 patients (7%), and 67 patients (94%) remained free of any functional deterioration during follow-up.
AVM flow analysis and categorization in terms of transit time are useful predictors of the probability of and the time to obliteration. The authors believe that a more quantitative understanding of flow can help to guide stereotactic radiosurgery treatment and set accurate outcome expectations.
Abstract
BACKGROUND:
Neuroform stent-assisted coil embolization facilitates the endovascular treatment of wide-necked intracranial aneurysms. However, the safety and efficacy of its long-term use ...have not been fully elucidated.
OBJECTIVE:
To retrospectively examine the long-term results of Neuroform stent usage in conjunction with coil embolization in wide-necked intracranial aneurysms.
METHODS:
Between November 2002 and December 2010, 79 patients harboring wide-necked intracranial aneurysms were treated with use of the Neuroform stent. The stenting procedure failed in 2 patients. Therefore, 77 patients harboring 79 intracranial aneurysms were included for analysis. Patient and aneurysm characteristics, progression of aneurysm occlusion, and occurrence of complications were analyzed. Follow-up imaging included digital subtraction angiography (DSA) or magnetic resonance angiography (MRA). Kaplan-Meier analysis, as well as univariate analysis were performed to determine the progression of aneurysm occlusion and to examine the predictive factors for complete aneurysm occlusion, respectively.
RESULTS:
Overall, complete aneurysm occlusion was observed in 42.4% of the cases immediately after treatment and progressed to 96.5% at 7-year follow-up. The mean angiographic follow-up time was 25.8 months (range, 0–84 months). Eleven aneurysms (14%) were re-treated. Sixty-eight patients (88.3%) had favorable clinical outcome with a modified Rankin Scale (mRS) ⩽ 1, 3 patients (3.9%) had an mRS of 2, and 5 patients (6.5%) did not have a clinical follow-up. The mean clinical follow-up time was 45.4 months (range, 3–92 months). One patient (1.3%) died of a procedure-related hemorrhage.
CONCLUSION:
Neuroform stent-assisted coil embolization of wide-necked intracranial aneurysms prevents hemorrhage and provides a high rate of aneurysm occlusion at long-term follow-up.
Background and Purpose
While the thrombotic complications of COVID-19 have been well described, there are limited data on clinically significant bleeding complications including hemorrhagic stroke. ...The clinical characteristics, underlying stroke mechanism, and outcomes in this particular subset of patients are especially salient as therapeutic anticoagulation becomes increasingly common in the treatment and prevention of thrombotic complications of COVID-19.
Methods
We conducted a retrospective cohort study of patients with hemorrhagic stroke (both non-traumatic intracerebral hemorrhage and spontaneous non-aneurysmal subarachnoid hemorrhage) who were hospitalized between March 1, 2020, and May 15, 2020, within a major healthcare system in New York, during the coronavirus pandemic. Patients with hemorrhagic stroke on admission and who developed hemorrhage during hospitalization were both included. We compared the clinical characteristics of patients with hemorrhagic stroke and COVID-19 to those without COVID-19 admitted to our hospital system between March 1, 2020, and May 15, 2020 (contemporary controls), and March 1, 2019, and May 15, 2019 (historical controls). Demographic variables and clinical characteristics between the individual groups were compared using Fischer’s exact test for categorical variables and nonparametric test for continuous variables. We adjusted for multiple comparisons using the Bonferroni method.
Results
During the study period in 2020, out of 4071 patients who were hospitalized with COVID-19, we identified 19 (0.5%) with hemorrhagic stroke. Of all COVID-19 with hemorrhagic stroke, only three had isolated non-aneurysmal SAH with no associated intraparenchymal hemorrhage. Among hemorrhagic stroke in patients with COVID-19, coagulopathy was the most common etiology (73.7%); empiric anticoagulation was started in 89.5% of these patients versus 4.2% in contemporary controls (
p
≤ .001) and 10.0% in historical controls (
p
≤ .001). Compared to contemporary and historical controls, patients with COVID-19 had higher initial NIHSS scores, INR, PTT, and fibrinogen levels. Patients with COVID-19 also had higher rates of in-hospital mortality (84.6% vs. 4.6%,
p
≤ 0.001). Sensitivity analyses excluding patients with strictly subarachnoid hemorrhage yielded similar results.
Conclusion
We observed an overall low rate of imaging-confirmed hemorrhagic stroke among patients hospitalized with COVID-19. Most hemorrhages in patients with COVID-19 infection occurred in the setting of therapeutic anticoagulation and were associated with increased mortality. Further studies are needed to evaluate the safety and efficacy of therapeutic anticoagulation in patients with COVID-19.
To evaluate the midterm results of intracranial stent-assisted coil embolization in the treatment of wide-necked cerebral aneurysms and to assess the efficacy of various strategies used in stent ...deployment.
A retrospective study of 42 patients with 46 wide-necked cerebral aneurysms enrolled in a prospective single-center registry of patients treated with a Neuroform stent (Boston Scientific/Target, Fremont, CA), a flexible self-expanding nitinol stent, was performed. Twenty-seven of 46 aneurysms were unruptured aneurysms, 14 were recanalized aneurysms, and five were acutely ruptured. Thirty-nine aneurysms were located in the anterior and seven in the posterior circulation. Mean aneurysm size was 9.8 mm. Stenting before coiling was performed in 13 of 45 aneurysms (29%), coiling before stenting in 27 of 45 aneurysms (60%), and stenting alone in five of 45 aneurysms (11%). The balloon remodeling technique for coiling before stenting was performed in 77% of patients. Angiographic and clinical follow up was available in 31 patients with 33 aneurysms and ranged from 3 to 24 months.
Neuroform stenting was attempted in 46 wide-necked aneurysms (42 patients). Forty-nine stent sessions were performed, including three poststent retreatments. In 46 of 49 sessions (94%), successful deployment of 47 stents for 45 aneurysms was obtained. In 40 aneurysms treated with stent-assisted coiling, angiographic results showed 14 (35%) aneurysm occlusions, 18 (45%) neck remnants, and eight (20%) residual aneurysms. In five recanalized aneurysms treated with stenting alone, no changes were observed in four (80%) aneurysms and one (20%) neck remnant reduced in size. At angiographic follow-up in 30 aneurysms treated with stent-assisted coiling, there were 17 (57%) aneurysm occlusions, seven (23%) neck remnants, and six (20%) residual aneurysms. In three recanalized aneurysms treated with stent alone, two (67%) neck remnants remained unchanged and one (33%) neck remnant decreased in size. Procedural morbidity was observed in two of 42 patients (4.8%) and one patient died. On clinical follow-up, the modified Rankin Scale score was 0 in 27 patients (87%), 1 in three patients (10%), and 2 (3%) in one patient. No aneurysm bled during the follow-up period.
These results indicate that Neuroform stent-assisted coil embolization is a safe and effective technique in the treatment of wide-necked cerebral aneurysms. Further studies are needed to evaluate the long-term durability of stent-assisted aneurysm occlusion and tolerance to the stent.
Endovascular embolization is typically reserved as an adjuvant therapy in the management of cerebral arteriovenous malformations (AVMs), either for preoperative devascularization or preradiosurgical ...volume reduction. Curative embolization plays a limited role in AVM treatment but several studies have shown that it is possible, especially with later-generation liquid embolic agents. Given the complexity of AVM anatomy and the recent controversies over the role of any intervention in AVM management, it is critical that the cerebrovascular community better define the indications of each treatment modality to provide quality AVM management. In this review, the authors evaluate the role of curative AVM embolization. Important considerations in the feasibility of curative AVM embolization include whether it can be performed reliably and safely, and whether it is a durable cure. Studies over the past 20 years have begun to define the anatomical factors that are amenable to complete endovascular occlusion, including size, feeding artery anatomy, AVM morphology, and endovascular accessibility. More recent studies have shown that highly selected patients with AVMs can be treated with curative intent, leading to occlusion rates as high as 100% of such prospectively identified lesions with minimal morbidity. Advances in endovascular technology and techniques that support the efficacy and safety of curative embolization are discussed, as is the importance of superselective diagnostic angiography. Finally, the durability of curative embolization is analyzed. Overall, while still unproven, endovascular embolization has the potential to be a safe, effective, and durable curative treatment for select AVMs, broadening the armamentarium with which one can treat this disease.
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