Persistent Opacification of the Woven EndoBridge Device: A Conebeam CT Analysis of the Bicêtre Occlusion Scale Score 1 Phenomenon.

BACKGROUND AND PURPOSE: Some Woven EndoBridge devices present a persistent intradevice opacification at imaging follow-up, described as the Bicêtre Occlusion Scale Score 1 (BOSS 1) phenomenon. The clinical implications remain unknown. We aimed here to analyze the factors influencing this occurrence and to precisely describe the evolution of BOSS 1 with time using conebeam CT. MATERIALS AND METHODS: We retrospectively analyzed a prospectively maintained Woven EndoBridge database at our tertiary center and included all patients with isolated BOSS 1 and BOSS 1 associated with small neck remnant (BOSS 1 + 2). RESULTS: Two hundred sixty-seven aneurysms were treated with a Woven EndoBridge device between July 2012 and December 2021. Follow-up with DSA was available for 220 aneurysms (median, 5 months), among which BOSS 1 and 1 + 2 were found in 9.1% (20/220) (95% CI, 5.5%-12.7%). A second DSA follow-up (median, 17 months) was performed in 15 of these 20 aneurysms, which revealed that 40% had evolved to complete Woven EndoBridge occlusion, 33% showed a decreased persistent opacification, and 27% remained stable. BOSS 1 was significantly associated with postoperative antiplatelet medication, a lower aneurysm aspect ratio, and the use of the Woven EndoBridge 17 (P < .05). The average Woven EndoBridge shape modification was less pronounced in the BOSS 1 population (P < .02). None of the BOSS 1 or 1 + 2 aneurysms required retreatment or were associated with hemorrhage occurrence. CONCLUSIONS: Isolated persistent flow inside the Woven EndoBridge device at follow-up is rare and notably associated with antiplatelet prescription. It seems to present a benign course in most cases.

Impact of A1 Asymmetry on the Woven EndoBridge Device in Anterior Communicating Artery Aneurysms.

BACKGROUND AND PURPOSE: Woven EndoBridge (WEB) devices are increasingly used to treat intracranial aneurysms. A1 asymmetry contributes to anterior communicating artery aneurysm formation and to treatment instability after coiling. We sought to evaluate whether A1 asymmetry had an impact on angiographic outcome in anterior communicating artery aneurysms treated with the WEB. MATERIALS AND METHODS: Anterior communicating artery aneurysms treated between July 2012 and July 2020 with the WEB from an institutional review board-approved database were reviewed. A1 asymmetry was categorized as the following: absence of the A1 segment on 1 side (unilateral A1) versus bilateral A1. Univariate and multivariable analyses assessed independent predictors of adequate (WEB Occlusion Scale A, B, and C) and complete occlusion (WEB Occlusion Scale A and B). RESULTS: Forty-eight individual aneurysms (47 patients) were included in the final analysis, of which 16 (33%) were acutely ruptured. The mean size was 6.5 (SD, 2.2) mm. Adequate and complete occlusion was achieved in 33 (69%) and 30 (63%) cases, respectively. Unilateral A1 was associated with significantly higher rates of adequate (92% versus 60% for bilateral A1; P = .03) and complete occlusion (92% versus 50% for bilateral A1; P < .01). Multivariable logistic regression confirmed unilateral A1 as an independent predictor of both adequate (OR = 10.6; 95% CI, 1.6-220.7; P = .04) and complete occlusion (OR = 9.5, 95% CI, 1.5-190.2; P = .04. A sensitivity analysis comparing unilateral "functional" A1 with bilateral "functional" A1 showed similar results. WEB shape modification was not influenced by the unilateral A1 configuration (P = .70). CONCLUSIONS: Anterior communicating artery aneurysms with a unilateral A1 configuration treated with WEB devices are associated with better angiographic outcome than those with bilateral A1. This finding supports the hypothesis that WEB devices are resistant to unilateral flow in the aneurysm as opposed to coils.

Endovascular Treatment of Small and Very Small Intracranial Aneurysms with the Woven EndoBridge Device.

BACKGROUND AND PURPOSE: The Woven EndoBridge has proved to be a safe and effective treatment, especially for wide-neck intracranial aneurysms. The recent fifth-generation Woven EndoBridge came with smaller devices. The purpose of this study was to assess the safety and efficiency of Woven EndoBridge treatment of small and very small aneurysms. MATERIALS AND METHODS: Between September 2017 and March 2020, all consecutive patients treated with a 3- or 3.5 mm-width Woven EndoBridge device were included in this retrospective intention-to-treat study. Clinical and radiologic findings were evaluated at immediate and last-available follow-up. Angiographic outcome was assessed by an external expert reader. RESULTS: One hundred twenty-eight aneurysms were treated with a fifth-generation Woven EndoBridge device including 29 with a width of ≤3.5 mm. Ten aneurysms were ruptured (34%). In 3 cases (10%), Woven EndoBridge treatment could not be performed because the aneurysm was still too small for the smallest available Woven EndoBridge device and another endovascular strategy was chosen. The median follow-up time was 11.2 months. Complete and adequate occlusion was obtained in 71% and 90% of the treated aneurysms, respectively. Retreatment was needed in 2 cases (10%). Symptomatic ischemic complications leading to transient neurologic deficits occurred in 2 cases (7%) (1 procedure-related and 1 device-related) but with full spontaneous recovery at discharge. CONCLUSIONS: The fifth-generation Woven EndoBridge device seems to be a safe and technically feasible treatment for both ruptured and unruptured small and very small intracranial aneurysms, with satisfactory occlusion rates on midterm follow-up. However, further study is needed to evaluate longer-term efficiency.

Large Basilar Apex Aneurysms Treated with Flow-Diverter Stents.

BACKGROUND AND PURPOSE: The treatment of wide-neck, large basilar apex aneurysms is challenging with either an endovascular or a surgical approach. The aim of the present study was to report our experience treating basilar apex aneurysms with flow-diverter stents and to evaluate their efficacy and safety profile in this specific anatomic condition. MATERIALS AND METHODS: We retrospectively analyzed data from all consecutive patients treated with flow-diverter stents at our institution between January 2011 and January 2015. Patients with large basilar apex aneurysms treated with a flow-diverter stent were included in the study. Clinical presentations, technical details, intra- and perioperative complications, and clinical and angiographic outcomes were recorded, with a midterm follow-up. RESULTS: Of the 175 aneurysms treated with flow-diverter stents at our institution, 5 patients (2 women and 3 men; age range, 44-58 years) received flow-diverter stent for basilar apex aneurysms. The mean follow-up after stent deployment was 21 months (range, 15-24 months). One patient died on day 31 from an early postprocedural midbrain hemorrhage. One patient had a right cerebellar hemispheric ischemic lesion with a transient cerebellar syndrome resolved within 24 hours without neurologic sequelae at the latest follow-up. The mRS was 0 in 4 patients and 6 in 1 patient at last follow-up. CONCLUSIONS: Flow diversion is a feasible technique with an efficacy demonstrated at a midterm follow-up, especially in the case of basilar apex aneurysm recurrences after previous endovascular treatments. Concern about its safety profile still exists.

Should indications for WEB aneurysm treatment be enlarged? Report of a series of 20 patients with aneurysms in "atypical" locations for WEB treatment.

BACKGROUND AND PURPOSE: Flow disruption with the WEB device is an innovative technique for the endovascular treatment of wide neck bifurcation aneurysms. Good clinical practice trials have shown high safety of this treatment with good efficacy. Technical developments (single layer devices and smaller microcatheters) facilitate the treatment, potentially leading to enlargement of indications. This series is collecting aneurysms in "atypical" locations for WEB treatment and analyzing safety and efficacy of this treatment. MATERIALS AND METHODS: In each participating center, patients with aneurysms treated with WEB were prospectively included in a local database. Patients treated for aneurysms in "atypical" locations were extracted. Patient and aneurysm characteristics, intraoperative complications, and anatomical results at the end of the procedure and at last follow-up were collected and analyzed. RESULTS: Five French neurointerventional centers included 20 patients with 20 aneurysms in "atypical" locations for WEB treatment treated with WEB. Aneurysm locations were ICA carotid-ophthalmic in 9 aneurysms (45.0%), ICA posterior communicating in 4 (20.0%), Pericallosal artery in 5 (25.0%), and basilar artery between P1 and superior cerebellar artery in 2 (10.0%). There were no complications (thromboembolic or intraoperative rupture) in this series. At follow-up (mean: 7.4 months), adequate occlusion was obtained in 100.0% of aneurysms. CONCLUSIONS: This series confirms that it is possible to enlarge indications of WEB treatment to "atypical" locations with good safety and efficacy. These data have to be confirmed in large prospective series.

The origin of the dorsal scapular artery: anatomic variations and surgical applications.

The dorsal scapular artery (DSA) can be either a direct branch of the subclavian artery (SCA), or a branch of the transverse cervical artery (TCA). In mandibular reconstruction, when a free flap is contraindicated a pedicled scapular flap has been described vascularized by the DSA. During the dissection of this flap, there is a risk of lesion of the TCA, which could be fatal to the flap if the DCA is a branch of the TCA. To evaluate the frequency of this anatomic situation, a dissection and radiologic study has been performed. 50 anatomic dissections on fresh cadavers and 93 arteriographies from 47 patients have been studied, to determine what was the DSA origin. In our dissections we found the origin of the DSA was a type I origin in 19 cases (38 %), a type II in 19 cases (38 %) and a type III in 12 cases (24 %). In our radiologic study, the DSA and the TCA had a common origin from the SCA (Type I) in 57/93 cases (61.3 %), the DSA was a direct branch of the SCA and the TCA (type II) in 22/93 cases (23.7 %), the DSA and the TCA had a common origin from the TCT (type III) in 14/93 cases (15 %). The DSA is coming from the TCA in 1/5 cases. A careful dissection of this flap in the subclavian area is necessary in all cases, a preoperative arteriography could be proposed to limit the risk of pedicle injury.

Flow-Diverter Stents for the Treatment of Saccular Middle Cerebral Artery Bifurcation Aneurysms.

BACKGROUND AND PURPOSE: The flow-diverter stent has been proved a feasible, safe, and efficient technique, particularly for the treatment of large and broad-neck carotid siphon aneurysms. Wide-neck bifurcation aneurysms remain, in some cases, a challenge for neurointerventionalists. We report the outcomes of the treatment of saccular middle cerebral artery bifurcation aneurysms with flow diversion in our institution. MATERIALS AND METHODS: From the institution data base, all saccular, nondissecting MCA bifurcation aneurysms, treated with flow-diverter stents, were retrospectively reviewed. Technical issues, immediate posttreatment and follow-up angiographic findings, and clinical outcomes were assessed. RESULTS: Fourteen patients with 15 aneurysms were included in the study. Ischemic complications, as confirmed by MR imaging, occurred in 6 patients (43%). Procedure-related morbidity and mortality at last follow-up were 21% and 0%, respectively. Angiographic follow-up was available for 13 aneurysms, with a mean follow-up of 16 months. Complete occlusion was obtained for 8 aneurysms (62%). CONCLUSIONS: Compared with other available therapeutic options, the flow-diverter stent does not appear to be a suitable solution for the treatment of saccular MCA bifurcation aneurysms.

Single-Layer WEBs: Intrasaccular Flow Disrupters for Aneurysm Treatment­Feasibility Results from a European Study.

BACKGROUND AND PURPOSE: The safety and efficiency of the dual-layer Woven EndoBridge (WEB) device has already been published. However, this international multicenter study sought to evaluate the safety of single-layer devices, which are the newest generation of the WEB intrasaccular flow-disrupter family. They have been designed to offer smaller-sized devices with a lower profile to optimize navigability and delivery, which may, in turn, broaden their range of use. MATERIALS AND METHODS: Data from all consecutive patients treated with a single-layer WEB device, in 10 European centers from June 2013 to May 2014 were included. Clinical presentations, technical details, intra- and perioperative complications, and outcomes at discharge were recorded. Clinical and angiographic data at last follow-up were also analyzed when available. RESULTS: Ninety patients with 98 WEB-treated aneurysms were included in this study. In 93 cases (95%), WEB placement was possible. Complete occlusion at the end of the procedure was obtained in 26 instances (26%). Additional treatment during the procedure (coiling and/or stent placement) was necessary in 12 cases (12.7%). Procedure-related complications occurred in 13 cases, leading to permanent neurologic deficits in 4 patients (4.4%). Early vascular imaging follow-up data were available for 44 patients (57%), with an average time interval of 3.3 months. Treatment-related morbidity and mortality rates at last follow-up were 2.2% and 1.1%, respectively. CONCLUSIONS: In this study, the feasibility and safety of the single-layer WEB device was comparable with that of the double-layer. However, further studies are needed to evaluate long-term efficacies.

Role of C-arm VasoCT in the use of endovascular WEB flow disruption in intracranial aneurysm treatment.

BACKGROUND AND PURPOSE: The WEB aneurysm embolization system is still under evaluation but seems to be a promising technique to treat wide-neck bifurcation aneurysms. However, this device is barely visible using conventional DSA; thus, high-resolution contrast-enhanced flat panel detector CT (VasoCT) may be useful before detachment to assess the sizing and positioning of the WEB. The purpose of this study was to evaluate the interest of VasoCT during WEB procedures. MATERIALS AND METHODS: From March 2012 to July 2013, twelve patients (10 women and 2 men; age range, 44-55 years) were treated for 13 intracranial aneurysms with the WEB device. DSA and VasoCT were used and compared to depict any protrusion of the device in parent arteries before detachment. Two neuroradiologists reviewed each VasoCT scan, and the quality was graded on a subjective quality scale. RESULTS: The mesh of the WEB was very well-depicted in all cases, allowing a very good assessment of its deployment. Device protrusion was clearly detected with VasoCT in 5 cases, leading to WEB repositioning or size substitution. During follow-up, VasoCT also allows good assessment of eventual residual blood flow inside the aneurysm or the WEB device. CONCLUSIONS: Unlike DSA, VasoCT is an excellent tool to assess WEB deployment and positioning. In our experience, it allowed a precise evaluation of the WEB sizing and its relation to the parent vessel. Such information very likely enhances the ability to safely use this device, avoiding potential thromboembolic events in cases of protrusion in the parent arteries.