WEB in Partially Thrombosed Intracranial Aneurysms: A Word of Caution

Endovascular Treatment of Bifurcation Aneurysms with the Woven EndoBridge: Product Features and Selected Results of Off-Label Use

Treatment for wide-neck bifurcation cerebral aneurysms (WNBAs) is widely performed by endovascular treatment as well as open surgical clipping. However, due to factors such as the shape and size of the aneurysms, as well as the anatomical features of surrounding branch vessels, there are some cases in which simple coiling or conventional adjunctive techniques, such as balloon-assisted or neck bridge stent-assisted coiling, are not sufficient to achieve a satisfactory cure. Against this backdrop, the device known as the Woven EndoBridge (WEB) (MicroVention, Aliso Viejo, CA, USA) was developed and can be deployed directly into the aneurysm for treatment. Over a decade has passed since its development, and it is now used in many countries worldwide. This review provides insights into the evolution of the WEB device from its development to the date of this writing, highlighting the unique features of the device and its treatment indications. Additionally, it discusses the posttreatment course, perspectives on recurrence and retreatment, imaging assessments, and potential off-label use based on numerous studies primarily conducted in Europe and the USA.

Single centre experience of stent-assisted coiling of wide-necked basilar tip aneurysms

OBJECTIVE

To report clinical and radiological follow-up outcomes of stent-assisted coiling of wide-necked basilar tip aneurysms and to evaluate the safety and efficacy of this treatment choice.

METHODS

A retrospective review was carried out of 19 patients with wide-necked basilar tip aneurysms in our institution between 2010 and 2020. The rates of perioperative complication, morbidity, mortality, imaging follow-up and re-treatment were analysed.

RESULTS

Our technical complication rate was 11% but did not result in treatment failure. The combined procedure related morbidity and mortality rate of the 19 patients who underwent stent assisted coiling was also 11%. 16 of 19 patients had undergone angiographic follow-up with a mean period of 32 months. 81% of patients with angiographic follow-up had a satisfactory occlusion (RROI or II) with 11% requiring re-treatment. Those requiring re-treatment were both treated with laser-cut stents; this is in contrast with no re-treatments required in the patients treated with braided stents.

CONCLUSION

Our report provides acceptable outcomes in wide-necked basilar termination aneurysms which are very challenging to treat. Aneurysms treated with braided stents had better efficacy outcomes than those with laser-cut stents.

ADVANCES IN KNOWLEDGE

Given the emergent and increasing utility of alternative endovascular techniques such as intrasaccular devices and flow diverters, real-world data are lacking on more conventional approaches such stent-assisted coiling, especially so in the posterior circulation. The associated relatively higher aneurysmal haemorrhagic risk in this location warrants further additional safety and efficacy data for this treatment approach, which this paper provides.

Contour-Assisted coiling with jailed microcatheter May result in better occlusion (CoCoJaMBO) in wide-necked intracranial aneurysms: Proof of principle and immediate angiographic results

PURPOSE

Wide-necked bifurcation aneurysms, partially thrombosed, and recurrences of large and giant aneurysms are challenging to treat. We report our preliminary experience with a Contour-assisted coiling technique and discuss the periprocedural safety, feasibility, and effectiveness of the approach.

METHODS

We retrospectively reviewed consecutive patients who received endovascular treatment for intracranial aneurysms with an intra-aneurysmal flow disruptor (Contour) at two neurovascular centres between October 2018 and December 2020 and identified patients treated with a combination of Contour and platinum coils. Clinical and procedural data were recorded.

RESULTS

For this analysis, 8 patients (5 female) aged 60.1  ±  9.2 years on average were identified. Three of 8 aneurysms were associated with previous acute subarachnoid hemorrhage (SAH). The mean average dome height was 12.8  ±  7.6 mm, mean maximum dome width 10.3  ±  5.4 mm, and neck width 5.5  ±  2.5 mm. The mean dome-to-neck ratio was 1.9  ±  1.0. Immediate complete occlusion of the aneurysm was seen in 5 of 8 cases. In one SAH patient, a parent vessel was temporarily occluded but could be reopened rapidly. One device detached prematurely without any sequelae. No other procedural adverse events were recorded.

CONCLUSION

From this initial experience, Contour with adjunctive coiling is a safe and technically feasible method for endovascular treatment of large, wide-necked, partially thrombosed, recurrent, or ruptured bifurcation aneurysms. Further studies with larger numbers of patients and longer follow-up are needed to confirm our results.

Comprehensive review of the recent advances in devices for endovascular treatment of complex brain aneurysms

The International Subarachnoid Aneurysm Trial (ISAT) showed superiority for endovascular treatment of ruptured aneurysms and technology has since moved on rapidly. Many approaches and technology now exist for the endovascular management of ruptured and unruptured intracranial aneurysms, which reflects their varied nature - there is no one-size-fits-all technique. We aim to provide an overview of the various classes of device and the major developments over the past decade. Coiling is the oldest of the technology and continues to demonstrate high levels of occlusion and acceptable risks, making it the default treatment choice, particularly in the acutely ruptured aneurysm setting. Advances on coiling include the use of adjuncts such as balloons, stents and fully retrievable temporary neck-bridging devices, which have facilitated the treatment of more complex aneurysms. Flow divertors have also revolutionised complex aneurysm treatment with small added risk in acute aneurysm treatment and seek to remodel the aneurysm-vessel interface without accessing the aneurysm sac. The latest development and most promising avenue appears to be intrasaccular flow disrupting devices like WEB, Contour and Neqstent that provide excellent opportunities to treat wide neck complex aneurysm with minimal mortality and morbidity and good occlusion rates and may in future replace a significant number of stent-assisted coiling too.

"Fountain Sign," a Basic Finding toward the Diagnosis of Partially Thrombosed Giant Aneurysm: Describing a Challenging Case and Literature Review

Although the occurrence of cerebral aneurysms in pediatric age group describes as rare, giant ones are more commonly be found than in adults. Insufficient epidemiological information, their association with other medical comorbidities, diagnostic pitfalls, complex surgical anatomy, and issues should be considered during surgery to make them difficult to diagnose and manage. We report a 6-year-old boy with presenting complaint of acute-onset headache without any other symptoms and a small area of intracerebral hemorrhage detected on initial computed tomography (CT) scan. Primary evaluations failed to result in a definite diagnosis, and delayed vascular studies suggested vascular malformation or an aneurysm as the causative factor of hemorrhage. Surgical exploration led to the diagnosis of a giant partially thrombosed aneurysm at the A2 segment of the left anterior cerebral artery and successful clipping. One of our findings on preoperative CT angiography, “fountain sign,” may be useful for the diagnosis of partially thrombosed aneurysms when active bleeding from the aneurysm has been ruled out. Fountain sign can be a useful finding in the diagnosis of partially thrombosed aneurysms. Vascular lesions should always be considered as the primary cause of intracranial hemorrhage in pediatrics despite negative initial studies. Therefore, close follow-up and using delayed and multimodality vascular evaluations are crucial for successful management.

Long-Term Outcome of Endovascular Therapy for Large or Giant Thrombosed Intracranial Aneurysms

OBJECTIVE

Large or giant thrombosed intracranial aneurysms (LGTIAs) are highly associated with poor prognosis and remain a challenging disease to treat by either surgery or endovascular treatment (EVT). EVT is considered more difficult for complicated aneurysm like LGTIAs. To understand long-term clinical and angiographic outcomes of EVT for LGTIAs, we retrospectively analyzed our single-center data on multimodality EVT for patients with LGTIAs.

METHODS

From the data of 35 EVT procedures performed in 31 consecutive patients with LGTIAs at our institution between December 2004 and December 2018, the rate of periprocedural complications, clinical outcomes at 12 months after EVT, and the rate of aneurysm recurrence were analyzed, and their related factors were evaluated.

RESULTS

Initial EVTs were performed by deconstructive (n = 10) or reconstructive (n = 21) techniques. Although 5 patients (16%) died during the periprocedural period, 23 (74%) had good outcome at 12 months after the procedures. Among 26 patients with long-term follow-up, aneurysm recurrence was observed in 6 patients (23.1%; median time from treatment, 33.2 months). Aneurysm recurrence was significantly higher in patients with basilar artery aneurysm (P = 0.0421) and stroke (P = 0.0307); however, there was no significant difference between the procedures and devices used.

CONCLUSIONS

Multimodality EVT for LGTIAs was performed with similar clinical outcomes and better radiologic outcomes compared with previous reports. New innovative techniques and devices are expected to be helpful for long-term aneurysm occlusion.

Woven Endobridge (WEB) Device as a Retreatment Strategy After Unsuccessful Surgical Clipping

BACKGROUND

Surgical clipping of intracranial aneurysms is typically robust and durable. However, residual aneurysmal components may be seen after clipping. Furthermore, there may be occasional aneurysmal recurrence. These factors are both clinically relevant because subarachnoid hemorrhage after clipping is a rare but important event. The rationale for any treatment is to substantially decrease the future risk of hemorrhage. Small series have shown coiling as a retreatment strategy after unsuccessful clipping, but none has explored the feasibility of Woven Endobridge (WEB) implantation.

CASE DESCRIPTION

We examined the feasibility of WEB implantation as second-line treatment for wide-necked residual aneurysms after unsuccessful clipping. We also recorded the safety and efficacy in this small series of 6 patients. To determine safety, we measured the modified Rankin Scale score before and after the procedure, and at 2 later time points (mean follow-up, 5 months and 15 months). To determine efficacy, we obtained radiographic aneurysm occlusion outcomes (including WEB Occlusion Scale) at these 2 time points. Four middle cerebral artery and 2 anterior communicating artery complex aneurysms were treated with WEB implantation, showing feasibility in 6/6 cases (100%). Follow-up at 15 months showed no change from preprocedural modified Rankin Scale score and there were no other complications. There was adequate occlusion in 5/6 cases (83%).

CONCLUSIONS

WEB implantation provided a feasible option in this challenging retreatment scenario. This is a small series and prospective data are required to make outcome inferences for this population. Nonetheless, we observed no complications and high adequate occlusion rates.

A Virtual Comparison of the eCLIPs Device and Conventional Flow-Diverters as Treatment for Cerebral Bifurcation Aneurysms

PURPOSE

Effective, consistent, and complication-free treatment of cerebral bifurcation aneurysms remains elusive despite a pressing need, with the majority of lesions presenting in such locations. Current treatment options focus either on aneurysm coil retention, supported by a stent-like device positioned in the parent vessel lumen, or intrasaccular devices that disrupt flow within the aneurysm dome. A third alternative, i.e., the use of conventional (intraluminal) flow-diverters to treat such bifurcation aneurysms raises the problem that at least one daughter vessel needs to be jailed in such a deployment. The eCLIPs is a stent-like device that offers the possibility of flow-diversion at the aneurysm neck, without the drawbacks of daughter vessel occlusion or those of intrasaccular deployment.

METHODS

In this study the eCLIPs device was virtually deployed in five cerebral bifurcation aneurysms and compared with a conventional tubular flow-diverter device. Computational fluid dynamics (CFD) simulations of the aneurysm haemodynamic environment pre- and post-implantation were conducted, and focussed on metrics associated with successful aneurysm occlusion. Absolute and relative reductions in aneurysm inflow rate (Q) and time-averaged wall shear stress (TAWSS) were recorded.

RESULTS

The eCLIPs device was found to perform in a similar qualitative fashion to tubular flow-diverters, with overall reduction of metrics being somewhat more modest however, when compared to such devices. Aneurysm inflow reduction and TAWSS reduction were typically 10-20% lower for the eCLIPs, when compared to a generic flow diverter (FD_BRAIDED) similar to devices currently in clinical use. The eCLIPs was less effective at diffusing inflow jets and at reducing the overall velocity of the flow, when compared to these devices. This result is likely due to the larger device pore size in the eCLIPs. Notably, it was found that the eCLIPs provided approximately equal resistance to flow entering and exiting the aneurysm, which was not true for the FD_BRAIDED device, where high-speed concentrations of outflow were seen at the aneurysm neck along with local TAWSS elevation. The clinical implications of such behaviour are not examined in detail here but could be significant.

CONCLUSIONS

Our findings indicate that the eCLIPs device acts as a flow-diverter for bifurcation aneurysms, with somewhat diminished occlusion properties comparing to tubular flow diverters but without the jailing and diminished flow evident in a daughter vessel associated with use of conventional devices.

The LUNA aneurysm embolization system for intracranial aneurysm treatment: short-term, mid-term and long-term clinical and angiographic results

BACKGROUND AND PURPOSE

Intrasaccular aneurysm flow disruption represents an emerging endovascular approach to treat intracranial aneurysms. The purpose of this study was to determine the clinical and angiographic outcomes of using the LUNA aneurysm embolization system (AES) for treatment of intracranial aneurysms.

MATERIALS AND METHODS

The LUNA AES Post-Market Clinical Follow-Up study is a prospective, multicenter, single-arm study that was designed to evaluate device safety and efficacy. Bifurcation and sidewall aneurysms were included. Aneurysm occlusion was assessed using the Raymond-Roy classification scale. Disability was assessed using the Modified Rankin Scale (mRS). Morbidity was defined as mRS >2 if baseline mRS ≤2, increase in mRS of 1 or more if baseline mRS >2, or mRS >2 if aneurysm was ruptured at baseline. Clinical and angiographic follow-up was conducted at 6, 12 and 36 months.

RESULTS

Sixty-three subjects with 64 aneurysms were enrolled. Most aneurysms were unruptured (60/63 (95.2%)); 49 were bifurcation or terminal (49/64 (76.6%)). Mean aneurysm size was 5.6±1.8 mm (range, 3.6-14.9 mm), and mean neck size was 3.8±1.0 mm (range, 1.9-8.7 mm). Though immediate postoperative adequate occlusion was low (11/63, 18%), adequate occlusion was achieved in 78.0% (46/59) and 79.2% (42/53) of the aneurysms at 12 months and 36 months, respectively. Four patients were retreated by the 12-month follow-up (4/63 (6.3%)) and three patients were retreated by the 36-month follow-up (3/63 (4.8%)). There were two major strokes (2/63 (3.2%)), one minor stroke (1/63 (1.6%)) and three incidents of intracranial hemorrhage in two subjects (2/63 (3.2%)) prior to the 12-month follow-up. There was one instance of mortality (1/63, 1.6%). Morbidity was 0% (0/63) and 1.8% (1/63) at the 12-month and 36-month follow-ups, respectively.

CONCLUSIONS

LUNA AES is safe and effective for the treatment of bifurcation and sidewall aneurysms.

CLINICAL TRIAL REGISTRATION

ISRCTN72343080; Results.

Endovascular treatment of intracranial aneurysms with the Woven EndoBridge device: mid term and long term results

Purpose

To evaluate the clinical and anatomical results of treatment of intracranial aneurysms (IA) with the Woven EndoBridge (WEB) device, with emphasis on mid term and long term follow-up.

Methods

Between November 2010 and November 2015, we retrospectively identified, in our prospectively maintained database, all patients treated by WEB device placement for an IA at three institutions. Clinical charts, procedural data, and angiographic results were reviewed.

Results

48 patients with 49 IAs were identified. There were 35 women and 13 men with a mean age of 57 years (range 35–76 years). All IA were wide necked. Mean aneurysm size was 8.6 mm. There were 44 unruptured IA and 5 ruptured IA. During endovascular treatment (EVT), adjunctive devices were used in 22.4% of procedures. A good clinical outcome (modified Rankin Scale score ≤2) was achieved in 44/48 patients (92%). There was no mortality. Mean follow-up was 25 months (range 3–72 months; median 24 months). Between mid term and long term follow-up, occlusion was stable in 19/23 IA (82.6%), improved in 2/23 IA (8.7%), and worsened in 2/23 IA (8.7%). Retreatment was performed in 8/49 IA (16.3%). At the latest available follow-up, there were 34/47 (72.3%) complete occlusions and 13/47 (27.7%) neck remnants.

Conclusions

Our study suggests that EVT of IA with the WEB device provides adequate and stable long term occlusion.

The Woven Endobridge Device for Treatment of Intracranial Aneurysms: A Systematic Review

INTRODUCTION

The Woven Endobridge (WEB) device is an innovative endovascular device for treatment of intracranial aneurysms, especially bifurcation and wide-neck aneurysms. Although not approved by the U.S. Food and Drug Administration, it has been available in Europe since 2011. The aim of this review is to evaluate the outcomes of WEB device use for intracranial aneurysm treatment.

METHODS

A systematic review was conducted with MEDLINE search engines PubMed and Embase from 2011. The search strategy provided 6229 articles, and 19 articles were included.

RESULTS

A total of 19 papers were identified describing the use of WEB devices in 687 patients with 718 aneurysms. The 2 largest prospective multicenter studies (WEBCAST and the French Observatory Trial) reported successful treatment, defined as complete closure or a neck remnant, in 85% and 79% of aneurysms, respectively. The use of a WEB device in combination with coiling or stenting was described with varying results in multiple small series. Outcomes of WEB device use in ruptured aneurysms in 2 studies showed 94% and 80% adequate treatment. Thromboembolic events were described in 71 patients (10.3% of all patients) and infarctions in 8 patients (1.2% of all patients).

CONCLUSIONS

Despite initial promising results, the WEB device should be used with caution given its potentially large learning curve and because it has primarily been investigated only in wide-neck and bifurcation aneurysms. In addition, currently available prospective studies have short follow-up, and the device has not been directly compared with other treatment modalities.